1 /* $NetBSD: viornd.c,v 1.9 2015/10/27 16:04:19 christos 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@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@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(vsc->sc_dmat, 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 virtio_enqueue_abort(vsc, vq, slot); 111 goto out; 112 } 113 virtio_enqueue(vsc, vq, slot, sc->sc_dmamap, 0); 114 virtio_enqueue_commit(vsc, vq, slot, 1); 115 sc->sc_active = true; 116 out: 117 mutex_exit(&sc->sc_mutex); 118 } 119 120 int 121 viornd_match(device_t parent, cfdata_t match, void *aux) 122 { 123 struct virtio_softc *va = aux; 124 if (va->sc_childdevid == PCI_PRODUCT_VIRTIO_ENTROPY) 125 return 1; 126 return 0; 127 } 128 129 void 130 viornd_attach( device_t parent, device_t self, void *aux) 131 { 132 struct viornd_softc *sc = device_private(self); 133 struct virtio_softc *vsc = device_private(parent); 134 bus_dma_segment_t segs[1]; 135 int nsegs; 136 int error; 137 uint32_t features; 138 char buf[256]; 139 140 vsc->sc_vqs = &sc->sc_vq; 141 vsc->sc_nvqs = 1; 142 vsc->sc_config_change = NULL; 143 if (vsc->sc_child != NULL) 144 panic("already attached to something else"); 145 vsc->sc_child = self; 146 vsc->sc_ipl = IPL_NET; 147 vsc->sc_intrhand = virtio_vq_intr; 148 sc->sc_virtio = vsc; 149 sc->sc_dev = self; 150 151 features = virtio_negotiate_features(vsc, 0); 152 snprintb(buf, sizeof(buf), VIRTIO_COMMON_FLAG_BITS, features); 153 aprint_normal(": Features: %s\n", buf); 154 aprint_naive("\n"); 155 156 157 mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_VM); 158 159 error = bus_dmamem_alloc(vsc->sc_dmat, 160 VIRTIO_PAGE_SIZE, 0, 0, segs, 1, &nsegs, 161 BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW); 162 if (error) { 163 aprint_error_dev(sc->sc_dev, "can't alloc dmamem: %d\n", 164 error); 165 goto alloc_failed; 166 } 167 168 error = bus_dmamem_map(vsc->sc_dmat, segs, nsegs, VIORND_BUFSIZE, 169 &sc->sc_buf, BUS_DMA_NOWAIT); 170 if (error) { 171 aprint_error_dev(sc->sc_dev, "can't map dmamem: %d\n", error); 172 goto map_failed; 173 } 174 175 error = bus_dmamap_create(vsc->sc_dmat, VIORND_BUFSIZE, 1, 176 VIORND_BUFSIZE, 0, 177 BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW, 178 &sc->sc_dmamap); 179 if (error) { 180 aprint_error_dev(sc->sc_dev, "can't alloc dmamap: %d\n", 181 error); 182 goto create_failed; 183 } 184 185 error = bus_dmamap_load(vsc->sc_dmat, sc->sc_dmamap, 186 sc->sc_buf, VIORND_BUFSIZE, NULL, 187 BUS_DMA_NOWAIT|BUS_DMA_READ); 188 if (error) { 189 aprint_error_dev(sc->sc_dev, "can't load dmamap: %d\n", 190 error); 191 goto load_failed; 192 } 193 194 error = virtio_alloc_vq(vsc, &sc->sc_vq, 0, VIORND_BUFSIZE, 1, 195 "Entropy request"); 196 if (error) { 197 aprint_error_dev(sc->sc_dev, "can't alloc virtqueue: %d\n", 198 error); 199 goto vio_failed; 200 } 201 202 sc->sc_vq.vq_done = viornd_vq_done; 203 virtio_start_vq_intr(vsc, &sc->sc_vq); 204 rndsource_setcb(&sc->sc_rndsource, viornd_get, sc); 205 rnd_attach_source(&sc->sc_rndsource, device_xname(sc->sc_dev), 206 RND_TYPE_RNG, 207 RND_FLAG_COLLECT_VALUE|RND_FLAG_HASCB); 208 viornd_get(VIORND_BUFSIZE, sc); 209 return; 210 vio_failed: 211 bus_dmamap_unload(vsc->sc_dmat, sc->sc_dmamap); 212 load_failed: 213 bus_dmamap_destroy(vsc->sc_dmat, sc->sc_dmamap); 214 create_failed: 215 bus_dmamem_unmap(vsc->sc_dmat, sc->sc_buf, VIORND_BUFSIZE); 216 map_failed: 217 bus_dmamem_free(vsc->sc_dmat, segs, nsegs); 218 alloc_failed: 219 vsc->sc_child = (void *)1; /* XXX bare constant 1 */ 220 return; 221 } 222 223 int 224 viornd_vq_done(struct virtqueue *vq) 225 { 226 struct virtio_softc *vsc = vq->vq_owner; 227 struct viornd_softc *sc = device_private(vsc->sc_child); 228 int slot, len; 229 230 mutex_enter(&sc->sc_mutex); 231 232 if (virtio_dequeue(vsc, vq, &slot, &len) != 0) { 233 mutex_exit(&sc->sc_mutex); 234 return 0; 235 } 236 237 sc->sc_active = false; 238 239 bus_dmamap_sync(vsc->sc_dmat, sc->sc_dmamap, 0, VIORND_BUFSIZE, 240 BUS_DMASYNC_POSTREAD); 241 if (len > VIORND_BUFSIZE) { 242 aprint_error_dev(sc->sc_dev, 243 "inconsistent descriptor length %d > %d\n", 244 len, VIORND_BUFSIZE); 245 goto out; 246 } 247 248 #if VIORND_DEBUG 249 aprint_normal("%s: got %d bytes of entropy\n", __func__, len); 250 #endif 251 rnd_add_data(&sc->sc_rndsource, sc->sc_buf, VIORND_BUFSIZE, 252 VIORND_BUFSIZE * NBBY); 253 out: 254 virtio_dequeue_commit(vsc, vq, slot); 255 mutex_exit(&sc->sc_mutex); 256 257 return 1; 258 } 259