Move viornd.c to sys/dev/pv/viornd.c

virtio itself is not PCI, it is a paravirtual bus on top of either PCI
or MMIO (arm).  This is the second step of moving the virtio files to
dev/pv.  No functional change.

Moving the file is done by removing and adding it again - the old
history can be found in the Attic of sys/dev/pci/viornd.c.

no objections from sf@ mlarkin@

1 files changed, 201 insertions, 0 deletions

diff --git a/sys/dev/pv/viornd.c b/sys/dev/pv/viornd.c
new file mode 100644
index 00000000000..dc0a43738b7
--- /dev/null
+++ b/sys/dev/pv/viornd.c
@@ -0,0 +1,201 @@
+/*	$OpenBSD: viornd.c,v 1.1 2017/01/21 11:22:48 reyk Exp $	*/
+
+/*
+ * Copyright (c) 2014 Stefan Fritsch <sf@sfritsch.de>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/timeout.h>
+#include <machine/bus.h>
+#include <sys/device.h>
+#include <sys/pool.h>
+#include <dev/rndvar.h>
+#include <dev/pv/virtioreg.h>
+#include <dev/pv/virtiovar.h>
+
+/*
+ * The host may not have an unlimited supply of entropy. Therefore, we must
+ * not blindly get as much entropy as we can. Instead, we just request
+ * VIORND_BUFSIZE bytes at boot and every 15 * (1 << interval_shift) seconds.
+ * XXX There should be an API to check if we actually need more entropy.
+ *
+ * The lowest byte in the flags is used for transport specific settings.
+ * Therefore we use the second byte.
+ */
+#define	VIORND_INTERVAL_SHIFT(f)	((f >> 8) & 0xf)
+#define	VIORND_INTERVAL_SHIFT_DEFAULT	5
+#define	VIORND_ONESHOT			0x1000
+#define	VIORND_BUFSIZE			16
+
+#define VIORND_DEBUG 0
+
+struct viornd_softc {
+	struct device		 sc_dev;
+	struct virtio_softc	*sc_virtio;
+
+	struct virtqueue         sc_vq;
+	int			*sc_buf;
+	bus_dmamap_t		 sc_dmamap;
+
+	unsigned int		 sc_interval;
+	struct timeout		 sc_tick;
+};
+
+int	viornd_match(struct device *, void *, void *);
+void	viornd_attach(struct device *, struct device *, void *);
+int	viornd_vq_done(struct virtqueue *);
+void	viornd_tick(void *);
+
+struct cfattach viornd_ca = {
+	sizeof(struct viornd_softc),
+	viornd_match,
+	viornd_attach,
+	NULL
+};
+
+struct cfdriver viornd_cd = {
+	NULL, "viornd", DV_DULL
+};
+
+
+int viornd_match(struct device *parent, void *match, void *aux)
+{
+	struct virtio_softc *va = aux;
+	if (va->sc_childdevid == PCI_PRODUCT_VIRTIO_ENTROPY)
+		return 1;
+	return 0;
+}
+
+void
+viornd_attach(struct device *parent, struct device *self, void *aux)
+{
+	struct viornd_softc *sc = (struct viornd_softc *)self;
+	struct virtio_softc *vsc = (struct virtio_softc *)parent;
+	unsigned int shift;
+
+	vsc->sc_vqs = &sc->sc_vq;
+	vsc->sc_nvqs = 1;
+	vsc->sc_config_change = 0;
+	if (vsc->sc_child != NULL)
+		panic("already attached to something else");
+	vsc->sc_child = self;
+	vsc->sc_ipl = IPL_NET;
+	sc->sc_virtio = vsc;
+
+	virtio_negotiate_features(vsc, 0, NULL);
+
+	if (sc->sc_dev.dv_cfdata->cf_flags & VIORND_ONESHOT) {
+		sc->sc_interval = 0;
+	} else {
+		shift = VIORND_INTERVAL_SHIFT(sc->sc_dev.dv_cfdata->cf_flags);
+		if (shift == 0)
+			shift = VIORND_INTERVAL_SHIFT_DEFAULT;
+		sc->sc_interval = 15 * (1 << shift);
+	}
+#if VIORND_DEBUG
+	printf(": request interval: %us\n", sc->sc_interval);
+#endif
+
+	sc->sc_buf = dma_alloc(VIORND_BUFSIZE, PR_NOWAIT|PR_ZERO);
+	if (sc->sc_buf == NULL) {
+		printf(": Can't alloc dma buffer\n");
+		goto err;
+	}
+	if (bus_dmamap_create(sc->sc_virtio->sc_dmat, VIORND_BUFSIZE, 1,
+	    VIORND_BUFSIZE, 0, BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW,
+	    &sc->sc_dmamap)) {
+		printf(": Can't alloc dmamap\n");
+		goto err;
+	}
+	if (bus_dmamap_load(sc->sc_virtio->sc_dmat, sc->sc_dmamap,
+	    sc->sc_buf, VIORND_BUFSIZE, NULL, BUS_DMA_NOWAIT|BUS_DMA_READ)) {
+		printf(": Can't load dmamap\n");
+		goto err2;
+	}
+
+	if (virtio_alloc_vq(vsc, &sc->sc_vq, 0, VIORND_BUFSIZE, 1,
+	    "Entropy request") != 0) {
+		printf(": Can't alloc virtqueue\n");
+		goto err2;
+	}
+
+	sc->sc_vq.vq_done = viornd_vq_done;
+	virtio_start_vq_intr(vsc, &sc->sc_vq);
+	timeout_set(&sc->sc_tick, viornd_tick, sc);
+	timeout_add(&sc->sc_tick, 1);
+
+	printf("\n");
+	return;
+err2:
+	bus_dmamap_destroy(vsc->sc_dmat, sc->sc_dmamap);
+err:
+	vsc->sc_child = VIRTIO_CHILD_ERROR;
+	if (sc->sc_buf != NULL) {
+		dma_free(sc->sc_buf, VIORND_BUFSIZE);
+		sc->sc_buf = NULL;
+	}
+	return;
+}
+
+int
+viornd_vq_done(struct virtqueue *vq)
+{
+	struct virtio_softc *vsc = vq->vq_owner;
+	struct viornd_softc *sc = (struct viornd_softc *)vsc->sc_child;
+	int slot, len, i;
+
+	if (virtio_dequeue(vsc, vq, &slot, &len) != 0)
+		return 0;
+	bus_dmamap_sync(vsc->sc_dmat, sc->sc_dmamap, 0, VIORND_BUFSIZE,
+	    BUS_DMASYNC_POSTREAD);
+	if (len > VIORND_BUFSIZE) {
+		printf("%s: inconsistent descriptor length %d > %d\n",
+		    sc->sc_dev.dv_xname, len, VIORND_BUFSIZE);
+		goto out;
+	}
+
+#if VIORND_DEBUG
+	printf("%s: got %d bytes of entropy\n", __func__, len);
+#endif
+	for (i = 0; (i + 1) * sizeof(int) <= len; i++)
+		add_true_randomness(sc->sc_buf[i]);
+
+	if (sc->sc_interval)
+		timeout_add_sec(&sc->sc_tick, sc->sc_interval);
+
+out:
+	virtio_dequeue_commit(vq, slot);
+	return 1;
+}
+
+void
+viornd_tick(void *arg)
+{
+	struct viornd_softc *sc = arg;
+	struct virtio_softc *vsc = sc->sc_virtio;
+	struct virtqueue *vq = &sc->sc_vq;
+	int slot;
+
+	bus_dmamap_sync(vsc->sc_dmat, sc->sc_dmamap, 0, VIORND_BUFSIZE,
+	    BUS_DMASYNC_PREREAD);
+	if (virtio_enqueue_prep(vq, &slot) != 0 ||
+	    virtio_enqueue_reserve(vq, slot, 1) != 0) {
+		panic("%s: virtqueue enqueue failed", sc->sc_dev.dv_xname);
+	}
+	virtio_enqueue(vq, slot, sc->sc_dmamap, 0);
+	virtio_enqueue_commit(vsc, vq, slot, 1);
+}