/* $NetBSD: viornd.c,v 1.11.12.2 2017/12/03 11:37:29 jdolecek Exp $ */ /* $OpenBSD: viornd.c,v 1.1 2014/01/21 21:14:58 sf Exp $ */ /* * Copyright (c) 2014 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Thor Lancelot Simon (tls@NetBSD.org). * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * Copyright (c) 2014 Stefan Fritsch * * 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 #include #include #include #include #include #include #include #include #include #include #include #define VIORND_BUFSIZE 32 #define VIORND_DEBUG 0 struct viornd_softc { device_t sc_dev; struct virtio_softc *sc_virtio; kmutex_t sc_mutex; bool sc_active; void *sc_buf; struct virtqueue sc_vq; bus_dmamap_t sc_dmamap; krndsource_t sc_rndsource; }; int viornd_match(device_t, cfdata_t, void *); void viornd_attach(device_t, device_t, void *); int viornd_vq_done(struct virtqueue *); CFATTACH_DECL_NEW(viornd, sizeof(struct viornd_softc), viornd_match, viornd_attach, NULL, NULL); static void viornd_get(size_t bytes, void *priv) { struct viornd_softc *sc = priv; struct virtio_softc *vsc = sc->sc_virtio; struct virtqueue *vq = &sc->sc_vq; int slot; #if VIORND_DEBUG aprint_normal("%s: asked for %d bytes of entropy\n", __func__, VIORND_BUFSIZE); #endif mutex_enter(&sc->sc_mutex); if (sc->sc_active) { goto out; } bus_dmamap_sync(virtio_dmat(vsc), sc->sc_dmamap, 0, VIORND_BUFSIZE, BUS_DMASYNC_PREREAD); if (virtio_enqueue_prep(vsc, vq, &slot)) { goto out; } if (virtio_enqueue_reserve(vsc, vq, slot, 1)) { goto out; } virtio_enqueue(vsc, vq, slot, sc->sc_dmamap, 0); virtio_enqueue_commit(vsc, vq, slot, 1); sc->sc_active = true; out: mutex_exit(&sc->sc_mutex); } int viornd_match(device_t parent, cfdata_t match, void *aux) { struct virtio_attach_args *va = aux; if (va->sc_childdevid == PCI_PRODUCT_VIRTIO_ENTROPY) return 1; return 0; } void viornd_attach(device_t parent, device_t self, void *aux) { struct viornd_softc *sc = device_private(self); struct virtio_softc *vsc = device_private(parent); bus_dma_segment_t segs[1]; int nsegs; int error; if (virtio_child(vsc) != NULL) panic("already attached to something else"); sc->sc_dev = self; sc->sc_virtio = vsc; mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_VM); error = bus_dmamem_alloc(virtio_dmat(vsc), VIRTIO_PAGE_SIZE, 0, 0, segs, 1, &nsegs, BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW); if (error) { aprint_error_dev(sc->sc_dev, "can't alloc dmamem: %d\n", error); goto alloc_failed; } error = bus_dmamem_map(virtio_dmat(vsc), segs, nsegs, VIORND_BUFSIZE, &sc->sc_buf, BUS_DMA_NOWAIT); if (error) { aprint_error_dev(sc->sc_dev, "can't map dmamem: %d\n", error); goto map_failed; } error = bus_dmamap_create(virtio_dmat(vsc), VIORND_BUFSIZE, 1, VIORND_BUFSIZE, 0, BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW, &sc->sc_dmamap); if (error) { aprint_error_dev(sc->sc_dev, "can't alloc dmamap: %d\n", error); goto create_failed; } error = bus_dmamap_load(virtio_dmat(vsc), sc->sc_dmamap, sc->sc_buf, VIORND_BUFSIZE, NULL, BUS_DMA_NOWAIT|BUS_DMA_READ); if (error) { aprint_error_dev(sc->sc_dev, "can't load dmamap: %d\n", error); goto load_failed; } virtio_child_attach_start(vsc, self, IPL_NET, &sc->sc_vq, NULL, virtio_vq_intr, 0, 0, VIRTIO_COMMON_FLAG_BITS); error = virtio_alloc_vq(vsc, &sc->sc_vq, 0, VIORND_BUFSIZE, 1, "Entropy request"); if (error) { aprint_error_dev(sc->sc_dev, "can't alloc virtqueue: %d\n", error); goto vio_failed; } sc->sc_vq.vq_done = viornd_vq_done; if (virtio_child_attach_finish(vsc) != 0) { virtio_free_vq(vsc, &sc->sc_vq); goto vio_failed; } rndsource_setcb(&sc->sc_rndsource, viornd_get, sc); rnd_attach_source(&sc->sc_rndsource, device_xname(sc->sc_dev), RND_TYPE_RNG, RND_FLAG_COLLECT_VALUE|RND_FLAG_HASCB); viornd_get(VIORND_BUFSIZE, sc); return; vio_failed: bus_dmamap_unload(virtio_dmat(vsc), sc->sc_dmamap); load_failed: bus_dmamap_destroy(virtio_dmat(vsc), sc->sc_dmamap); create_failed: bus_dmamem_unmap(virtio_dmat(vsc), sc->sc_buf, VIORND_BUFSIZE); map_failed: bus_dmamem_free(virtio_dmat(vsc), segs, nsegs); alloc_failed: virtio_child_attach_failed(vsc); return; } int viornd_vq_done(struct virtqueue *vq) { struct virtio_softc *vsc = vq->vq_owner; struct viornd_softc *sc = device_private(virtio_child(vsc)); int slot, len; mutex_enter(&sc->sc_mutex); if (virtio_dequeue(vsc, vq, &slot, &len) != 0) { mutex_exit(&sc->sc_mutex); return 0; } sc->sc_active = false; bus_dmamap_sync(virtio_dmat(vsc), sc->sc_dmamap, 0, VIORND_BUFSIZE, BUS_DMASYNC_POSTREAD); if (len > VIORND_BUFSIZE) { aprint_error_dev(sc->sc_dev, "inconsistent descriptor length %d > %d\n", len, VIORND_BUFSIZE); goto out; } #if VIORND_DEBUG aprint_normal("%s: got %d bytes of entropy\n", __func__, len); #endif rnd_add_data(&sc->sc_rndsource, sc->sc_buf, VIORND_BUFSIZE, VIORND_BUFSIZE * NBBY); out: virtio_dequeue_commit(vsc, vq, slot); mutex_exit(&sc->sc_mutex); return 1; }