xref: /netbsd-src/sys/dev/virtio/virtio_mmio.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /*	$NetBSD: virtio_mmio.c,v 1.2 2018/06/15 17:13:43 jakllsch Exp $	*/
2 /*	$OpenBSD: virtio_mmio.c,v 1.2 2017/02/24 17:12:31 patrick Exp $	*/
3 
4 /*
5  * Copyright (c) 2014 Patrick Wildt <patrick@blueri.se>
6  * Copyright (c) 2012 Stefan Fritsch.
7  * Copyright (c) 2010 Minoura Makoto.
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __KERNEL_RCSID(0, "$NetBSD: virtio_mmio.c,v 1.2 2018/06/15 17:13:43 jakllsch Exp $");
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/device.h>
38 #include <sys/mutex.h>
39 
40 #define VIRTIO_PRIVATE
41 #include <dev/virtio/virtio_mmiovar.h>
42 
43 #define VIRTIO_MMIO_MAGIC		('v' | 'i' << 8 | 'r' << 16 | 't' << 24)
44 
45 #define VIRTIO_MMIO_MAGIC_VALUE		0x000
46 #define VIRTIO_MMIO_VERSION		0x004
47 #define VIRTIO_MMIO_DEVICE_ID		0x008
48 #define VIRTIO_MMIO_VENDOR_ID		0x00c
49 #define VIRTIO_MMIO_HOST_FEATURES	0x010
50 #define VIRTIO_MMIO_HOST_FEATURES_SEL	0x014
51 #define VIRTIO_MMIO_GUEST_FEATURES	0x020
52 #define VIRTIO_MMIO_GUEST_FEATURES_SEL	0x024
53 #define VIRTIO_MMIO_GUEST_PAGE_SIZE	0x028
54 #define VIRTIO_MMIO_QUEUE_SEL		0x030
55 #define VIRTIO_MMIO_QUEUE_NUM_MAX	0x034
56 #define VIRTIO_MMIO_QUEUE_NUM		0x038
57 #define VIRTIO_MMIO_QUEUE_ALIGN		0x03c
58 #define VIRTIO_MMIO_QUEUE_PFN		0x040
59 #define VIRTIO_MMIO_QUEUE_NOTIFY	0x050
60 #define VIRTIO_MMIO_INTERRUPT_STATUS	0x060
61 #define VIRTIO_MMIO_INTERRUPT_ACK	0x064
62 #define VIRTIO_MMIO_STATUS		0x070
63 #define VIRTIO_MMIO_CONFIG		0x100
64 
65 #define VIRTIO_MMIO_INT_VRING		(1 << 0)
66 #define VIRTIO_MMIO_INT_CONFIG		(1 << 1)
67 
68 /*
69  * XXX: Before being used on big endian arches, the access to config registers
70  * XXX: needs to be reviewed/fixed. The non-device specific registers are
71  * XXX: PCI-endian while the device specific registers are native endian.
72  */
73 
74 static void	virtio_mmio_kick(struct virtio_softc *, uint16_t);
75 static uint8_t	virtio_mmio_read_device_config_1(struct virtio_softc *, int);
76 static uint16_t	virtio_mmio_read_device_config_2(struct virtio_softc *, int);
77 static uint32_t	virtio_mmio_read_device_config_4(struct virtio_softc *, int);
78 static uint64_t	virtio_mmio_read_device_config_8(struct virtio_softc *, int);
79 static void	virtio_mmio_write_device_config_1(struct virtio_softc *, int, uint8_t);
80 static void	virtio_mmio_write_device_config_2(struct virtio_softc *, int, uint16_t);
81 static void	virtio_mmio_write_device_config_4(struct virtio_softc *, int, uint32_t);
82 static void	virtio_mmio_write_device_config_8(struct virtio_softc *, int, uint64_t);
83 static uint16_t	virtio_mmio_read_queue_size(struct virtio_softc *, uint16_t);
84 static void	virtio_mmio_setup_queue(struct virtio_softc *, uint16_t, uint32_t);
85 static void	virtio_mmio_set_status(struct virtio_softc *, int);
86 static uint32_t	virtio_mmio_negotiate_features(struct virtio_softc *, uint32_t);
87 static int	virtio_mmio_setup_interrupts(struct virtio_softc *);
88 static void	virtio_mmio_free_interrupts(struct virtio_softc *);
89 
90 static const struct virtio_ops virtio_mmio_ops = {
91 	.kick = virtio_mmio_kick,
92 	.read_dev_cfg_1 = virtio_mmio_read_device_config_1,
93 	.read_dev_cfg_2 = virtio_mmio_read_device_config_2,
94 	.read_dev_cfg_4 = virtio_mmio_read_device_config_4,
95 	.read_dev_cfg_8 = virtio_mmio_read_device_config_8,
96 	.write_dev_cfg_1 = virtio_mmio_write_device_config_1,
97 	.write_dev_cfg_2 = virtio_mmio_write_device_config_2,
98 	.write_dev_cfg_4 = virtio_mmio_write_device_config_4,
99 	.write_dev_cfg_8 = virtio_mmio_write_device_config_8,
100 	.read_queue_size = virtio_mmio_read_queue_size,
101 	.setup_queue = virtio_mmio_setup_queue,
102 	.set_status = virtio_mmio_set_status,
103 	.neg_features = virtio_mmio_negotiate_features,
104 	.setup_interrupts = virtio_mmio_setup_interrupts,
105 	.free_interrupts = virtio_mmio_free_interrupts,
106 };
107 
108 static uint16_t
109 virtio_mmio_read_queue_size(struct virtio_softc *vsc, uint16_t idx)
110 {
111 	struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc;
112 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_SEL, idx);
113 	return bus_space_read_4(sc->sc_iot, sc->sc_ioh,
114 	    VIRTIO_MMIO_QUEUE_NUM_MAX);
115 }
116 
117 static void
118 virtio_mmio_setup_queue(struct virtio_softc *vsc, uint16_t idx, uint32_t addr)
119 {
120 	struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc;
121 
122 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_SEL, idx);
123 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_NUM,
124 	    bus_space_read_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_NUM_MAX));
125 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_ALIGN,
126 	    VIRTIO_PAGE_SIZE);
127 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_PFN, addr);
128 }
129 
130 static void
131 virtio_mmio_set_status(struct virtio_softc *vsc, int status)
132 {
133 	struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc;
134 	int old = 0;
135 
136 	if (status != 0)
137 		old = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
138 				       VIRTIO_MMIO_STATUS);
139 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_STATUS,
140 			  status|old);
141 }
142 
143 void
144 virtio_mmio_common_attach(struct virtio_mmio_softc *sc)
145 {
146 	struct virtio_softc *vsc = &sc->sc_sc;
147 	uint32_t id, magic, ver;
148 
149 	magic = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
150 	    VIRTIO_MMIO_MAGIC_VALUE);
151 	if (magic != VIRTIO_MMIO_MAGIC) {
152 		aprint_error_dev(vsc->sc_dev,
153 		    "wrong magic value 0x%08x; giving up\n", magic);
154 		return;
155 	}
156 
157 	ver = bus_space_read_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_VERSION);
158 	if (ver != 1) {
159 		aprint_error_dev(vsc->sc_dev,
160 		    "unknown version 0x%02x; giving up\n", ver);
161 		return;
162 	}
163 
164 	id = bus_space_read_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_DEVICE_ID);
165 
166 	/* we could use PAGE_SIZE, but virtio(4) assumes 4KiB for now */
167 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_GUEST_PAGE_SIZE,
168 	    VIRTIO_PAGE_SIZE);
169 
170 	/* No device connected. */
171 	if (id == 0)
172 		return;
173 
174 	vsc->sc_ops = &virtio_mmio_ops;
175 
176 	virtio_device_reset(vsc);
177 	virtio_mmio_set_status(vsc, VIRTIO_CONFIG_DEVICE_STATUS_ACK);
178 	virtio_mmio_set_status(vsc, VIRTIO_CONFIG_DEVICE_STATUS_DRIVER);
179 
180 	/* XXX: use softc as aux... */
181 	vsc->sc_childdevid = id;
182 	vsc->sc_child = NULL;
183 }
184 
185 int
186 virtio_mmio_common_detach(struct virtio_mmio_softc *sc, int flags)
187 {
188 	struct virtio_softc *vsc = &sc->sc_sc;
189 	int r;
190 
191 	if (vsc->sc_child != NULL && vsc->sc_child != VIRTIO_CHILD_FAILED) {
192 		r = config_detach(vsc->sc_child, flags);
193 		if (r)
194 			return r;
195 	}
196 	KASSERT(vsc->sc_child == NULL || vsc->sc_child == VIRTIO_CHILD_FAILED);
197 	KASSERT(vsc->sc_vqs == NULL);
198 	KASSERT(sc->sc_ih == NULL);
199 
200 	if (sc->sc_iosize) {
201 		bus_space_unmap(sc->sc_iot, sc->sc_ioh, sc->sc_iosize);
202 		sc->sc_iosize = 0;
203 	}
204 
205 	return 0;
206 }
207 
208 /*
209  * Feature negotiation.
210  */
211 static uint32_t
212 virtio_mmio_negotiate_features(struct virtio_softc *vsc, uint32_t
213     guest_features)
214 {
215 	struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc;
216 	uint32_t r;
217 
218 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
219 	    VIRTIO_MMIO_HOST_FEATURES_SEL, 0);
220 	r = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
221 				VIRTIO_MMIO_HOST_FEATURES);
222 	r &= guest_features;
223 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
224 	    VIRTIO_MMIO_GUEST_FEATURES_SEL, 0);
225 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
226 			  VIRTIO_MMIO_GUEST_FEATURES, r);
227 	return r;
228 }
229 
230 /*
231  * Device configuration registers.
232  */
233 static uint8_t
234 virtio_mmio_read_device_config_1(struct virtio_softc *vsc, int index)
235 {
236 	struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc;
237 	return bus_space_read_1(sc->sc_iot, sc->sc_ioh,
238 				VIRTIO_MMIO_CONFIG + index);
239 }
240 
241 static uint16_t
242 virtio_mmio_read_device_config_2(struct virtio_softc *vsc, int index)
243 {
244 	struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc;
245 	return bus_space_read_2(sc->sc_iot, sc->sc_ioh,
246 				VIRTIO_MMIO_CONFIG + index);
247 }
248 
249 static uint32_t
250 virtio_mmio_read_device_config_4(struct virtio_softc *vsc, int index)
251 {
252 	struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc;
253 	return bus_space_read_4(sc->sc_iot, sc->sc_ioh,
254 				VIRTIO_MMIO_CONFIG + index);
255 }
256 
257 static uint64_t
258 virtio_mmio_read_device_config_8(struct virtio_softc *vsc, int index)
259 {
260 	struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc;
261 	uint64_t r;
262 
263 	r = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
264 			     VIRTIO_MMIO_CONFIG + index + sizeof(uint32_t));
265 	r <<= 32;
266 	r += bus_space_read_4(sc->sc_iot, sc->sc_ioh,
267 			      VIRTIO_MMIO_CONFIG + index);
268 	return r;
269 }
270 
271 static void
272 virtio_mmio_write_device_config_1(struct virtio_softc *vsc,
273 			     int index, uint8_t value)
274 {
275 	struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc;
276 	bus_space_write_1(sc->sc_iot, sc->sc_ioh,
277 			  VIRTIO_MMIO_CONFIG + index, value);
278 }
279 
280 static void
281 virtio_mmio_write_device_config_2(struct virtio_softc *vsc,
282 			     int index, uint16_t value)
283 {
284 	struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc;
285 	bus_space_write_2(sc->sc_iot, sc->sc_ioh,
286 			  VIRTIO_MMIO_CONFIG + index, value);
287 }
288 
289 static void
290 virtio_mmio_write_device_config_4(struct virtio_softc *vsc,
291 			     int index, uint32_t value)
292 {
293 	struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc;
294 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
295 			  VIRTIO_MMIO_CONFIG + index, value);
296 }
297 
298 static void
299 virtio_mmio_write_device_config_8(struct virtio_softc *vsc,
300 			     int index, uint64_t value)
301 {
302 	struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc;
303 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
304 			  VIRTIO_MMIO_CONFIG + index,
305 			  value & 0xffffffff);
306 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
307 			  VIRTIO_MMIO_CONFIG + index + sizeof(uint32_t),
308 			  value >> 32);
309 }
310 
311 /*
312  * Interrupt handler.
313  */
314 int
315 virtio_mmio_intr(void *arg)
316 {
317 	struct virtio_mmio_softc *sc = arg;
318 	struct virtio_softc *vsc = &sc->sc_sc;
319 	int isr, r = 0;
320 
321 	/* check and ack the interrupt */
322 	isr = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
323 			       VIRTIO_MMIO_INTERRUPT_STATUS);
324 	bus_space_write_4(sc->sc_iot, sc->sc_ioh,
325 			  VIRTIO_MMIO_INTERRUPT_ACK, isr);
326 	if ((isr & VIRTIO_MMIO_INT_CONFIG) &&
327 	    (vsc->sc_config_change != NULL))
328 		r = (vsc->sc_config_change)(vsc);
329 	if ((isr & VIRTIO_MMIO_INT_VRING) &&
330 	    (vsc->sc_intrhand != NULL)) {
331 		if (vsc->sc_soft_ih != NULL)
332 			softint_schedule(vsc->sc_soft_ih);
333 		else
334 			r |= (vsc->sc_intrhand)(vsc);
335 	}
336 
337 	return r;
338 }
339 
340 static void
341 virtio_mmio_kick(struct virtio_softc *vsc, uint16_t idx)
342 {
343 	struct virtio_mmio_softc *sc = (struct virtio_mmio_softc *)vsc;
344 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, VIRTIO_MMIO_QUEUE_NOTIFY,
345 	    idx);
346 }
347 
348 static int
349 virtio_mmio_setup_interrupts(struct virtio_softc *vsc)
350 {
351 	struct virtio_mmio_softc * const sc = (struct virtio_mmio_softc *)vsc;
352 
353 	return sc->sc_setup_interrupts(sc);
354 }
355 
356 static void
357 virtio_mmio_free_interrupts(struct virtio_softc *vsc)
358 {
359 	struct virtio_mmio_softc * const sc = (struct virtio_mmio_softc *)vsc;
360 
361 	sc->sc_free_interrupts(sc);
362 }
363