viornd.c revision 1.11
1 /* $NetBSD: viornd.c,v 1.11 2017/03/25 18:02:06 jdolecek 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/rndsource.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 0 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 #if VIORND_DEBUG 95 aprint_normal("%s: asked for %d bytes of entropy\n", __func__, 96 VIORND_BUFSIZE); 97 #endif 98 mutex_enter(&sc->sc_mutex); 99 100 if (sc->sc_active) { 101 goto out; 102 } 103 104 bus_dmamap_sync(virtio_dmat(vsc), sc->sc_dmamap, 0, VIORND_BUFSIZE, 105 BUS_DMASYNC_PREREAD); 106 if (virtio_enqueue_prep(vsc, vq, &slot)) { 107 goto out; 108 } 109 if (virtio_enqueue_reserve(vsc, vq, slot, 1)) { 110 goto out; 111 } 112 virtio_enqueue(vsc, vq, slot, sc->sc_dmamap, 0); 113 virtio_enqueue_commit(vsc, vq, slot, 1); 114 sc->sc_active = true; 115 out: 116 mutex_exit(&sc->sc_mutex); 117 } 118 119 int 120 viornd_match(device_t parent, cfdata_t match, void *aux) 121 { 122 struct virtio_attach_args *va = aux; 123 124 if (va->sc_childdevid == PCI_PRODUCT_VIRTIO_ENTROPY) 125 return 1; 126 127 return 0; 128 } 129 130 void 131 viornd_attach(device_t parent, device_t self, void *aux) 132 { 133 struct viornd_softc *sc = device_private(self); 134 struct virtio_softc *vsc = device_private(parent); 135 bus_dma_segment_t segs[1]; 136 int nsegs; 137 int error; 138 139 if (virtio_child(vsc) != NULL) 140 panic("already attached to something else"); 141 142 sc->sc_dev = self; 143 sc->sc_virtio = vsc; 144 145 mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_VM); 146 147 error = bus_dmamem_alloc(virtio_dmat(vsc), 148 VIRTIO_PAGE_SIZE, 0, 0, segs, 1, &nsegs, 149 BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW); 150 if (error) { 151 aprint_error_dev(sc->sc_dev, "can't alloc dmamem: %d\n", 152 error); 153 goto alloc_failed; 154 } 155 156 error = bus_dmamem_map(virtio_dmat(vsc), segs, nsegs, VIORND_BUFSIZE, 157 &sc->sc_buf, BUS_DMA_NOWAIT); 158 if (error) { 159 aprint_error_dev(sc->sc_dev, "can't map dmamem: %d\n", error); 160 goto map_failed; 161 } 162 163 error = bus_dmamap_create(virtio_dmat(vsc), VIORND_BUFSIZE, 1, 164 VIORND_BUFSIZE, 0, 165 BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW, 166 &sc->sc_dmamap); 167 if (error) { 168 aprint_error_dev(sc->sc_dev, "can't alloc dmamap: %d\n", 169 error); 170 goto create_failed; 171 } 172 173 error = bus_dmamap_load(virtio_dmat(vsc), sc->sc_dmamap, 174 sc->sc_buf, VIORND_BUFSIZE, NULL, 175 BUS_DMA_NOWAIT|BUS_DMA_READ); 176 if (error) { 177 aprint_error_dev(sc->sc_dev, "can't load dmamap: %d\n", 178 error); 179 goto load_failed; 180 } 181 182 virtio_child_attach_start(vsc, self, IPL_NET, &sc->sc_vq, 183 NULL, virtio_vq_intr, 0, 184 0, VIRTIO_COMMON_FLAG_BITS); 185 186 error = virtio_alloc_vq(vsc, &sc->sc_vq, 0, VIORND_BUFSIZE, 1, 187 "Entropy request"); 188 if (error) { 189 aprint_error_dev(sc->sc_dev, "can't alloc virtqueue: %d\n", 190 error); 191 goto vio_failed; 192 } 193 sc->sc_vq.vq_done = viornd_vq_done; 194 195 if (virtio_child_attach_finish(vsc) != 0) { 196 virtio_free_vq(vsc, &sc->sc_vq); 197 goto vio_failed; 198 } 199 200 rndsource_setcb(&sc->sc_rndsource, viornd_get, sc); 201 rnd_attach_source(&sc->sc_rndsource, device_xname(sc->sc_dev), 202 RND_TYPE_RNG, 203 RND_FLAG_COLLECT_VALUE|RND_FLAG_HASCB); 204 viornd_get(VIORND_BUFSIZE, sc); 205 206 return; 207 208 vio_failed: 209 bus_dmamap_unload(virtio_dmat(vsc), sc->sc_dmamap); 210 load_failed: 211 bus_dmamap_destroy(virtio_dmat(vsc), sc->sc_dmamap); 212 create_failed: 213 bus_dmamem_unmap(virtio_dmat(vsc), sc->sc_buf, VIORND_BUFSIZE); 214 map_failed: 215 bus_dmamem_free(virtio_dmat(vsc), segs, nsegs); 216 alloc_failed: 217 virtio_child_attach_failed(vsc); 218 return; 219 } 220 221 int 222 viornd_vq_done(struct virtqueue *vq) 223 { 224 struct virtio_softc *vsc = vq->vq_owner; 225 struct viornd_softc *sc = device_private(virtio_child(vsc)); 226 int slot, len; 227 228 mutex_enter(&sc->sc_mutex); 229 230 if (virtio_dequeue(vsc, vq, &slot, &len) != 0) { 231 mutex_exit(&sc->sc_mutex); 232 return 0; 233 } 234 235 sc->sc_active = false; 236 237 bus_dmamap_sync(virtio_dmat(vsc), sc->sc_dmamap, 0, VIORND_BUFSIZE, 238 BUS_DMASYNC_POSTREAD); 239 if (len > VIORND_BUFSIZE) { 240 aprint_error_dev(sc->sc_dev, 241 "inconsistent descriptor length %d > %d\n", 242 len, VIORND_BUFSIZE); 243 goto out; 244 } 245 246 #if VIORND_DEBUG 247 aprint_normal("%s: got %d bytes of entropy\n", __func__, len); 248 #endif 249 rnd_add_data(&sc->sc_rndsource, sc->sc_buf, VIORND_BUFSIZE, 250 VIORND_BUFSIZE * NBBY); 251 out: 252 virtio_dequeue_commit(vsc, vq, slot); 253 mutex_exit(&sc->sc_mutex); 254 255 return 1; 256 } 257
Indexes created Tue Sep 30 20:09:53 GMT 2025