254 lines
7.2 KiB
C
254 lines
7.2 KiB
C
/* $NetBSD: viornd.c,v 1.12 2018/06/10 14:59:23 jakllsch Exp $ */
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/* $OpenBSD: viornd.c,v 1.1 2014/01/21 21:14:58 sf Exp $ */
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/*
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* Copyright (c) 2014 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Thor Lancelot Simon (tls@NetBSD.org).
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Copyright (c) 2014 Stefan Fritsch <sf@sfritsch.de>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/device.h>
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#include <sys/callout.h>
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#include <sys/rndsource.h>
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#include <sys/mutex.h>
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#include <dev/pci/virtioreg.h>
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#include <dev/pci/virtiovar.h>
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#define VIORND_BUFSIZE 32
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#define VIORND_DEBUG 0
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struct viornd_softc {
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device_t sc_dev;
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struct virtio_softc *sc_virtio;
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kmutex_t sc_mutex;
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bool sc_active;
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void *sc_buf;
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struct virtqueue sc_vq;
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bus_dmamap_t sc_dmamap;
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krndsource_t sc_rndsource;
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};
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int viornd_match(device_t, cfdata_t, void *);
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void viornd_attach(device_t, device_t, void *);
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int viornd_vq_done(struct virtqueue *);
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CFATTACH_DECL_NEW(viornd, sizeof(struct viornd_softc),
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viornd_match, viornd_attach, NULL, NULL);
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static void
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viornd_get(size_t bytes, void *priv)
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{
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struct viornd_softc *sc = priv;
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struct virtio_softc *vsc = sc->sc_virtio;
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struct virtqueue *vq = &sc->sc_vq;
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int slot;
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#if VIORND_DEBUG
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aprint_normal("%s: asked for %d bytes of entropy\n", __func__,
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VIORND_BUFSIZE);
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#endif
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mutex_enter(&sc->sc_mutex);
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if (sc->sc_active) {
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goto out;
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}
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bus_dmamap_sync(virtio_dmat(vsc), sc->sc_dmamap, 0, VIORND_BUFSIZE,
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BUS_DMASYNC_PREREAD);
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if (virtio_enqueue_prep(vsc, vq, &slot)) {
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goto out;
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}
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if (virtio_enqueue_reserve(vsc, vq, slot, 1)) {
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goto out;
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}
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virtio_enqueue(vsc, vq, slot, sc->sc_dmamap, 0);
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virtio_enqueue_commit(vsc, vq, slot, 1);
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sc->sc_active = true;
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out:
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mutex_exit(&sc->sc_mutex);
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}
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int
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viornd_match(device_t parent, cfdata_t match, void *aux)
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{
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struct virtio_attach_args *va = aux;
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if (va->sc_childdevid == PCI_PRODUCT_VIRTIO_ENTROPY)
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return 1;
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return 0;
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}
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void
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viornd_attach(device_t parent, device_t self, void *aux)
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{
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struct viornd_softc *sc = device_private(self);
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struct virtio_softc *vsc = device_private(parent);
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bus_dma_segment_t segs[1];
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int nsegs;
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int error;
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if (virtio_child(vsc) != NULL)
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panic("already attached to something else");
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sc->sc_dev = self;
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sc->sc_virtio = vsc;
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mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_VM);
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error = bus_dmamem_alloc(virtio_dmat(vsc),
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VIRTIO_PAGE_SIZE, 0, 0, segs, 1, &nsegs,
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BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW);
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if (error) {
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aprint_error_dev(sc->sc_dev, "can't alloc dmamem: %d\n",
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error);
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goto alloc_failed;
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}
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error = bus_dmamem_map(virtio_dmat(vsc), segs, nsegs, VIORND_BUFSIZE,
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&sc->sc_buf, BUS_DMA_NOWAIT);
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if (error) {
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aprint_error_dev(sc->sc_dev, "can't map dmamem: %d\n", error);
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goto map_failed;
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}
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error = bus_dmamap_create(virtio_dmat(vsc), VIORND_BUFSIZE, 1,
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VIORND_BUFSIZE, 0,
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BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW,
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&sc->sc_dmamap);
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if (error) {
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aprint_error_dev(sc->sc_dev, "can't alloc dmamap: %d\n",
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error);
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goto create_failed;
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}
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error = bus_dmamap_load(virtio_dmat(vsc), sc->sc_dmamap,
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sc->sc_buf, VIORND_BUFSIZE, NULL,
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BUS_DMA_NOWAIT|BUS_DMA_READ);
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if (error) {
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aprint_error_dev(sc->sc_dev, "can't load dmamap: %d\n",
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error);
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goto load_failed;
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}
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virtio_child_attach_start(vsc, self, IPL_NET, &sc->sc_vq,
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NULL, virtio_vq_intr, 0,
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0, VIRTIO_COMMON_FLAG_BITS);
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error = virtio_alloc_vq(vsc, &sc->sc_vq, 0, VIORND_BUFSIZE, 1,
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"Entropy request");
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if (error) {
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aprint_error_dev(sc->sc_dev, "can't alloc virtqueue: %d\n",
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error);
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goto vio_failed;
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}
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sc->sc_vq.vq_done = viornd_vq_done;
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if (virtio_child_attach_finish(vsc) != 0) {
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virtio_free_vq(vsc, &sc->sc_vq);
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goto vio_failed;
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}
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rndsource_setcb(&sc->sc_rndsource, viornd_get, sc);
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rnd_attach_source(&sc->sc_rndsource, device_xname(sc->sc_dev),
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RND_TYPE_RNG,
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RND_FLAG_COLLECT_VALUE|RND_FLAG_HASCB);
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viornd_get(VIORND_BUFSIZE, sc);
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return;
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vio_failed:
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bus_dmamap_unload(virtio_dmat(vsc), sc->sc_dmamap);
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load_failed:
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bus_dmamap_destroy(virtio_dmat(vsc), sc->sc_dmamap);
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create_failed:
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bus_dmamem_unmap(virtio_dmat(vsc), sc->sc_buf, VIORND_BUFSIZE);
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map_failed:
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bus_dmamem_free(virtio_dmat(vsc), segs, nsegs);
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alloc_failed:
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virtio_child_attach_failed(vsc);
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return;
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}
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int
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viornd_vq_done(struct virtqueue *vq)
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{
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struct virtio_softc *vsc = vq->vq_owner;
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struct viornd_softc *sc = device_private(virtio_child(vsc));
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int slot, len;
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mutex_enter(&sc->sc_mutex);
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if (virtio_dequeue(vsc, vq, &slot, &len) != 0) {
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mutex_exit(&sc->sc_mutex);
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return 0;
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}
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sc->sc_active = false;
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bus_dmamap_sync(virtio_dmat(vsc), sc->sc_dmamap, 0, VIORND_BUFSIZE,
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BUS_DMASYNC_POSTREAD);
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if (len > VIORND_BUFSIZE) {
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aprint_error_dev(sc->sc_dev,
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"inconsistent descriptor length %d > %d\n",
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len, VIORND_BUFSIZE);
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goto out;
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}
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#if VIORND_DEBUG
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aprint_normal("%s: got %d bytes of entropy\n", __func__, len);
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#endif
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rnd_add_data(&sc->sc_rndsource, sc->sc_buf, VIORND_BUFSIZE,
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VIORND_BUFSIZE * NBBY);
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out:
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virtio_dequeue_commit(vsc, vq, slot);
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mutex_exit(&sc->sc_mutex);
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return 1;
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}
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