1/*-
2 * Copyright (c) 2014-2015 Ruslan Bukin <br@bsdpad.com>
3 * All rights reserved.
4 *
5 * This software was developed by SRI International and the University of
6 * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
7 * ("CTSRD"), as part of the DARPA CRASH research programme.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31/*
32 * BERI interface for Virtio MMIO bus.
33 *
34 * This driver provides interrupt-engine for software-implemented
35 * Virtio MMIO backend.
36 */
37
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD$");
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/bus.h>
44#include <sys/kernel.h>
45#include <sys/module.h>
46#include <sys/malloc.h>
47#include <sys/rman.h>
48#include <sys/timeet.h>
49#include <sys/timetc.h>
50#include <sys/watchdog.h>
51
52#include <machine/bus.h>
53#include <machine/fdt.h>
54#include <machine/cpu.h>
55#include <machine/cache.h>
56
57#include <dev/fdt/fdt_common.h>
58#include <dev/ofw/openfirm.h>
59#include <dev/ofw/ofw_bus.h>
60#include <dev/ofw/ofw_bus_subr.h>
61
62#include <dev/beri/virtio/virtio_mmio_platform.h>
63#include <dev/virtio/mmio/virtio_mmio.h>
64#include <dev/altera/pio/pio.h>
65
66#include "virtio_mmio_if.h"
67#include "pio_if.h"
68
69static void platform_intr(void *arg);
70
71struct virtio_mmio_platform_softc {
72	struct resource		*res[1];
73	void			*ih;
74	bus_space_tag_t		bst;
75	bus_space_handle_t	bsh;
76	device_t		dev;
77	void			(*intr_handler)(void *);
78	void			*ih_user;
79	device_t		pio_recv;
80	device_t		pio_send;
81	int			use_pio;
82};
83
84static int
85setup_pio(struct virtio_mmio_platform_softc *sc, char *name, device_t *dev)
86{
87	phandle_t pio_node;
88	struct fdt_ic *ic;
89	phandle_t xref;
90	phandle_t node;
91
92	if ((node = ofw_bus_get_node(sc->dev)) == -1)
93		return (ENXIO);
94
95	if (OF_searchencprop(node, name, &xref,
96		sizeof(xref)) == -1) {
97		return (ENXIO);
98	}
99
100	pio_node = OF_node_from_xref(xref);
101	SLIST_FOREACH(ic, &fdt_ic_list_head, fdt_ics) {
102		if (ic->iph == pio_node) {
103			*dev = ic->dev;
104			PIO_CONFIGURE(*dev, PIO_OUT_ALL,
105					PIO_UNMASK_ALL);
106			return (0);
107		}
108	}
109
110	return (ENXIO);
111}
112
113static int
114virtio_mmio_platform_probe(device_t dev)
115{
116
117	if (!ofw_bus_status_okay(dev))
118		return (ENXIO);
119
120	if (!ofw_bus_is_compatible(dev, "beri,virtio_mmio_platform"))
121		return (ENXIO);
122
123	device_set_desc(dev, "Virtio MMIO platform");
124	return (BUS_PROBE_DEFAULT);
125}
126
127static int
128virtio_mmio_platform_attach(device_t dev)
129{
130	struct virtio_mmio_platform_softc *sc;
131	struct fdt_ic *fic;
132	phandle_t node;
133
134	sc = device_get_softc(dev);
135	sc->dev = dev;
136	sc->use_pio = 1;
137
138	if ((setup_pio(sc, "pio-send", &sc->pio_send) != 0) ||
139	    (setup_pio(sc, "pio-recv", &sc->pio_recv) != 0))
140		sc->use_pio = 0;
141
142	if ((node = ofw_bus_get_node(sc->dev)) == -1)
143		return (ENXIO);
144
145	fic = malloc(sizeof(*fic), M_DEVBUF, M_WAITOK|M_ZERO);
146	fic->iph = node;
147	fic->dev = dev;
148	SLIST_INSERT_HEAD(&fdt_ic_list_head, fic, fdt_ics);
149
150	return (0);
151}
152
153static int
154platform_prewrite(device_t dev, size_t offset, int val)
155{
156	struct virtio_mmio_platform_softc *sc;
157
158	sc = device_get_softc(dev);
159
160	switch (offset) {
161	case (VIRTIO_MMIO_QUEUE_NOTIFY):
162		mips_dcache_wbinv_all();
163		break;
164	default:
165		break;
166	}
167
168	return (0);
169}
170
171static int
172platform_note(device_t dev, size_t offset, int val)
173{
174	struct virtio_mmio_platform_softc *sc;
175	int note;
176	int i;
177
178	sc = device_get_softc(dev);
179
180	switch (offset) {
181	case (VIRTIO_MMIO_QUEUE_NOTIFY):
182		if (val == 0)
183			note = Q_NOTIFY;
184		else if (val == 1)
185			note = Q_NOTIFY1;
186		else
187			note = 0;
188		break;
189	case (VIRTIO_MMIO_QUEUE_PFN):
190		note = Q_PFN;
191		break;
192	case (VIRTIO_MMIO_QUEUE_SEL):
193		note = Q_SEL;
194		break;
195	default:
196		note = 0;
197	}
198
199	if (note) {
200		mips_dcache_wbinv_all();
201
202		if (!sc->use_pio)
203			return (0);
204
205		PIO_SET(sc->pio_send, note, 1);
206
207		/*
208		 * Wait until host ack the request.
209		 * Usually done within few cycles.
210		 * TODO: bad
211		 */
212
213		for (i = 100; i > 0; i--) {
214			if (PIO_READ(sc->pio_send) == 0)
215				break;
216		}
217
218		if (i == 0)
219			device_printf(sc->dev, "Warning: host busy\n");
220	}
221
222	return (0);
223}
224
225static void
226platform_intr(void *arg)
227{
228	struct virtio_mmio_platform_softc *sc;
229	int reg;
230
231	sc = arg;
232
233	if (sc->use_pio) {
234		/* Read pending */
235		reg = PIO_READ(sc->pio_recv);
236
237		/* Ack */
238		PIO_SET(sc->pio_recv, reg, 0);
239	}
240
241	/* Writeback, invalidate cache */
242	mips_dcache_wbinv_all();
243
244	if (sc->intr_handler != NULL)
245		sc->intr_handler(sc->ih_user);
246}
247
248static int
249platform_setup_intr(device_t dev, device_t mmio_dev,
250			void *intr_handler, void *ih_user)
251{
252	struct virtio_mmio_platform_softc *sc;
253	int rid;
254
255	sc = device_get_softc(dev);
256
257	sc->intr_handler = intr_handler;
258	sc->ih_user = ih_user;
259
260	if (sc->use_pio) {
261		PIO_SETUP_IRQ(sc->pio_recv, platform_intr, sc);
262		return (0);
263	}
264
265	rid = 0;
266	sc->res[0] = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
267		RF_ACTIVE);
268	if (!sc->res[0]) {
269		device_printf(dev, "Can't allocate interrupt\n");
270		return (ENXIO);
271	}
272
273	if (bus_setup_intr(dev, sc->res[0], INTR_TYPE_MISC | INTR_MPSAFE,
274		NULL, platform_intr, sc, &sc->ih)) {
275		device_printf(dev, "Can't setup the interrupt\n");
276		return (ENXIO);
277	}
278
279	return (0);
280}
281
282static int
283platform_poll(device_t dev)
284{
285
286	mips_dcache_wbinv_all();
287
288	return (0);
289}
290
291static device_method_t virtio_mmio_platform_methods[] = {
292	DEVMETHOD(device_probe,		virtio_mmio_platform_probe),
293	DEVMETHOD(device_attach,	virtio_mmio_platform_attach),
294
295	/* virtio_mmio_if.h */
296	DEVMETHOD(virtio_mmio_prewrite,		platform_prewrite),
297	DEVMETHOD(virtio_mmio_note,		platform_note),
298	DEVMETHOD(virtio_mmio_poll,		platform_poll),
299	DEVMETHOD(virtio_mmio_setup_intr,	platform_setup_intr),
300	DEVMETHOD_END
301};
302
303static driver_t virtio_mmio_platform_driver = {
304	"virtio_mmio_platform",
305	virtio_mmio_platform_methods,
306	sizeof(struct virtio_mmio_platform_softc),
307};
308
309static devclass_t virtio_mmio_platform_devclass;
310
311DRIVER_MODULE(virtio_mmio_platform, simplebus, virtio_mmio_platform_driver,
312	virtio_mmio_platform_devclass, 0, 0);
313