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 | |