viornd.c revision 1.2
1 /* $NetBSD: viornd.c,v 1.2 2014/11/06 00:41:33 pooka Exp $ */ 2 /* $OpenBSD: viornd.c,v 1.1 2014/01/21 21:14:58 sf Exp $ */ 3 4 /* 5 * Copyright (c) 2014 The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Thor Lancelot Simon (tls (at) NetBSD.org). 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 2014 Stefan Fritsch <sf (at) sfritsch.de> 35 * 36 * Permission to use, copy, modify, and distribute this software for any 37 * purpose with or without fee is hereby granted, provided that the above 38 * copyright notice and this permission notice appear in all copies. 39 * 40 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 41 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 42 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 43 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 44 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 45 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 46 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 47 */ 48 49 #include <sys/param.h> 50 #include <sys/systm.h> 51 #include <sys/kernel.h> 52 #include <sys/device.h> 53 #include <sys/callout.h> 54 #include <sys/rnd.h> 55 #include <sys/mutex.h> 56 #include <dev/pci/pcidevs.h> 57 #include <dev/pci/pcivar.h> 58 #include <dev/pci/pcivar.h> 59 #include <dev/pci/virtioreg.h> 60 #include <dev/pci/virtiovar.h> 61 62 #define VIORND_BUFSIZE 32 63 64 #define VIORND_DEBUG 1 65 66 struct viornd_softc { 67 device_t sc_dev; 68 struct virtio_softc *sc_virtio; 69 70 kmutex_t sc_mutex; 71 bool sc_active; 72 73 void *sc_buf; 74 struct virtqueue sc_vq; 75 bus_dmamap_t sc_dmamap; 76 krndsource_t sc_rndsource; 77 }; 78 79 int viornd_match(device_t, cfdata_t, void *); 80 void viornd_attach(device_t, device_t, void *); 81 int viornd_vq_done(struct virtqueue *); 82 83 CFATTACH_DECL_NEW(viornd, sizeof(struct viornd_softc), 84 viornd_match, viornd_attach, NULL, NULL); 85 86 static void 87 viornd_get(size_t bytes, void *priv) 88 { 89 struct viornd_softc *sc = priv; 90 struct virtio_softc *vsc = sc->sc_virtio; 91 struct virtqueue *vq = &sc->sc_vq; 92 int slot; 93 94 aprint_normal("%s: asked for %d bytes of entropy\n", __func__, 95 VIORND_BUFSIZE); 96 mutex_enter(&sc->sc_mutex); 97 98 if (sc->sc_active) { 99 goto out; 100 } 101 102 bus_dmamap_sync(vsc->sc_dmat, sc->sc_dmamap, 0, VIORND_BUFSIZE, 103 BUS_DMASYNC_PREREAD); 104 if (virtio_enqueue_prep(vsc, vq, &slot)) { 105 virtio_enqueue_abort(vsc, vq, slot); 106 goto out; 107 } 108 if (virtio_enqueue_reserve(vsc, vq, slot, 1)) { 109 goto out; 110 } 111 virtio_enqueue(vsc, vq, slot, sc->sc_dmamap, 0); 112 virtio_enqueue_commit(vsc, vq, slot, 1); 113 sc->sc_active = true; 114 out: 115 mutex_exit(&sc->sc_mutex); 116 } 117 118 int 119 viornd_match(device_t parent, cfdata_t match, void *aux) 120 { 121 struct virtio_softc *va = aux; 122 if (va->sc_childdevid == PCI_PRODUCT_VIRTIO_ENTROPY) 123 return 1; 124 return 0; 125 } 126 127 void 128 viornd_attach( device_t parent, device_t self, void *aux) 129 { 130 struct viornd_softc *sc = device_private(self); 131 struct virtio_softc *vsc = device_private(parent); 132 bus_dma_segment_t segs[1]; 133 int nsegs; 134 int error; 135 136 vsc->sc_vqs = &sc->sc_vq; 137 vsc->sc_nvqs = 1; 138 vsc->sc_config_change = 0; 139 if (vsc->sc_child != NULL) 140 panic("already attached to something else"); 141 vsc->sc_child = self; 142 vsc->sc_ipl = IPL_NET; 143 vsc->sc_intrhand = virtio_vq_intr; 144 sc->sc_virtio = vsc; 145 sc->sc_dev = self; 146 147 aprint_normal("\n"); 148 aprint_naive("\n"); 149 150 (void)virtio_negotiate_features(vsc, 0); 151 152 mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_VM); 153 154 error = bus_dmamem_alloc(vsc->sc_dmat, 155 VIRTIO_PAGE_SIZE, 0, 0, segs, 1, &nsegs, 156 BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW); 157 if (error) { 158 aprint_error_dev(sc->sc_dev, "can't alloc dmamem: %d\n", 159 error); 160 goto alloc_failed; 161 } 162 163 error = bus_dmamem_map(vsc->sc_dmat, segs, nsegs, VIORND_BUFSIZE, 164 &sc->sc_buf, BUS_DMA_NOWAIT); 165 if (error) { 166 aprint_error_dev(sc->sc_dev, "can't map dmamem: %d\n", error); 167 goto map_failed; 168 } 169 170 error = bus_dmamap_create(vsc->sc_dmat, VIORND_BUFSIZE, 1, 171 VIORND_BUFSIZE, 0, 172 BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW, 173 &sc->sc_dmamap); 174 if (error) { 175 aprint_error_dev(sc->sc_dev, "can't alloc dmamap: %d\n", 176 error); 177 goto create_failed; 178 } 179 180 error = bus_dmamap_load(vsc->sc_dmat, sc->sc_dmamap, 181 sc->sc_buf, VIORND_BUFSIZE, NULL, 182 BUS_DMA_NOWAIT|BUS_DMA_READ); 183 if (error) { 184 aprint_error_dev(sc->sc_dev, "can't load dmamap: %d\n", 185 error); 186 goto load_failed; 187 } 188 189 error = virtio_alloc_vq(vsc, &sc->sc_vq, 0, VIORND_BUFSIZE, 1, 190 "Entropy request"); 191 if (error) { 192 aprint_error_dev(sc->sc_dev, "can't alloc virtqueue: %d\n", 193 error); 194 goto vio_failed; 195 } 196 197 sc->sc_vq.vq_done = viornd_vq_done; 198 virtio_start_vq_intr(vsc, &sc->sc_vq); 199 rndsource_setcb(&sc->sc_rndsource, viornd_get, sc); 200 rnd_attach_source(&sc->sc_rndsource, device_xname(sc->sc_dev), 201 RND_TYPE_RNG, 202 RND_FLAG_COLLECT_VALUE|RND_FLAG_HASCB); 203 viornd_get(VIORND_BUFSIZE, sc); 204 return; 205 vio_failed: 206 load_failed: 207 bus_dmamap_destroy(vsc->sc_dmat, sc->sc_dmamap); 208 create_failed: 209 bus_dmamem_unmap(vsc->sc_dmat, sc->sc_buf, VIORND_BUFSIZE); 210 map_failed: 211 bus_dmamem_free(vsc->sc_dmat, segs, nsegs); 212 alloc_failed: 213 vsc->sc_child = (void *)1; /* XXX bare constant 1 */ 214 return; 215 } 216 217 int 218 viornd_vq_done(struct virtqueue *vq) 219 { 220 struct virtio_softc *vsc = vq->vq_owner; 221 struct viornd_softc *sc = device_private(vsc->sc_child); 222 int slot, len; 223 224 mutex_enter(&sc->sc_mutex); 225 226 if (virtio_dequeue(vsc, vq, &slot, &len) != 0) { 227 mutex_exit(&sc->sc_mutex); 228 return 0; 229 } 230 231 sc->sc_active = false; 232 233 bus_dmamap_sync(vsc->sc_dmat, sc->sc_dmamap, 0, VIORND_BUFSIZE, 234 BUS_DMASYNC_POSTREAD); 235 if (len > VIORND_BUFSIZE) { 236 aprint_error_dev(sc->sc_dev, 237 "inconsistent descriptor length %d > %d\n", 238 len, VIORND_BUFSIZE); 239 goto out; 240 } 241 242 #if VIORND_DEBUG 243 aprint_normal("%s: got %d bytes of entropy\n", __func__, len); 244 #endif 245 rnd_add_data(&sc->sc_rndsource, sc->sc_buf, VIORND_BUFSIZE, 246 VIORND_BUFSIZE * NBBY); 247 out: 248 virtio_dequeue_commit(vsc, vq, slot); 249 mutex_exit(&sc->sc_mutex); 250 251 return 1; 252 } 253
Indexes created Wed Oct 01 07:09:59 GMT 2025