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/param.h>
39#include <sys/systm.h>
40#include <sys/bus.h>
41#include <sys/kernel.h>
42#include <sys/module.h>
43#include <sys/malloc.h>
44#include <sys/rman.h>
45#include <sys/timeet.h>
46#include <sys/timetc.h>
47#include <sys/watchdog.h>
48
49#include <machine/bus.h>
50#include <machine/fdt.h>
51#include <machine/cpu.h>
52#include <machine/cache.h>
53
54#include <dev/fdt/fdt_common.h>
55#include <dev/ofw/openfirm.h>
56#include <dev/ofw/ofw_bus.h>
57#include <dev/ofw/ofw_bus_subr.h>
58
59#include <dev/beri/virtio/virtio_mmio_platform.h>
60#include <dev/virtio/mmio/virtio_mmio.h>
61#include <dev/altera/pio/pio.h>
62
63#include "virtio_mmio_if.h"
64#include "pio_if.h"
65
66static void platform_intr(void *arg);
67
68struct virtio_mmio_platform_softc {
69	struct resource		*res[1];
70	void			*ih;
71	bus_space_tag_t		bst;
72	bus_space_handle_t	bsh;
73	device_t		dev;
74	void			(*intr_handler)(void *);
75	void			*ih_user;
76	device_t		pio_recv;
77	device_t		pio_send;
78	int			use_pio;
79};
80
81static int
82setup_pio(struct virtio_mmio_platform_softc *sc, char *name, device_t *dev)
83{
84	phandle_t pio_node;
85	struct fdt_ic *ic;
86	phandle_t xref;
87	phandle_t node;
88
89	if ((node = ofw_bus_get_node(sc->dev)) == -1)
90		return (ENXIO);
91
92	if (OF_searchencprop(node, name, &xref,
93		sizeof(xref)) == -1) {
94		return (ENXIO);
95	}
96
97	pio_node = OF_node_from_xref(xref);
98	SLIST_FOREACH(ic, &fdt_ic_list_head, fdt_ics) {
99		if (ic->iph == pio_node) {
100			*dev = ic->dev;
101			PIO_CONFIGURE(*dev, PIO_OUT_ALL,
102					PIO_UNMASK_ALL);
103			return (0);
104		}
105	}
106
107	return (ENXIO);
108}
109
110static int
111virtio_mmio_platform_probe(device_t dev)
112{
113
114	if (!ofw_bus_status_okay(dev))
115		return (ENXIO);
116
117	if (!ofw_bus_is_compatible(dev, "beri,virtio_mmio_platform"))
118		return (ENXIO);
119
120	device_set_desc(dev, "Virtio MMIO platform");
121	return (BUS_PROBE_DEFAULT);
122}
123
124static int
125virtio_mmio_platform_attach(device_t dev)
126{
127	struct virtio_mmio_platform_softc *sc;
128	struct fdt_ic *fic;
129	phandle_t node;
130
131	sc = device_get_softc(dev);
132	sc->dev = dev;
133	sc->use_pio = 1;
134
135	if ((setup_pio(sc, "pio-send", &sc->pio_send) != 0) ||
136	    (setup_pio(sc, "pio-recv", &sc->pio_recv) != 0))
137		sc->use_pio = 0;
138
139	if ((node = ofw_bus_get_node(sc->dev)) == -1)
140		return (ENXIO);
141
142	fic = malloc(sizeof(*fic), M_DEVBUF, M_WAITOK|M_ZERO);
143	fic->iph = node;
144	fic->dev = dev;
145	SLIST_INSERT_HEAD(&fdt_ic_list_head, fic, fdt_ics);
146
147	return (0);
148}
149
150static int
151platform_prewrite(device_t dev, size_t offset, int val)
152{
153	struct virtio_mmio_platform_softc *sc;
154
155	sc = device_get_softc(dev);
156
157	switch (offset) {
158	case (VIRTIO_MMIO_QUEUE_NOTIFY):
159		mips_dcache_wbinv_all();
160		break;
161	default:
162		break;
163	}
164
165	return (0);
166}
167
168static int
169platform_note(device_t dev, size_t offset, int val)
170{
171	struct virtio_mmio_platform_softc *sc;
172	int note;
173	int i;
174
175	sc = device_get_softc(dev);
176
177	switch (offset) {
178	case (VIRTIO_MMIO_QUEUE_NOTIFY):
179		if (val == 0)
180			note = Q_NOTIFY;
181		else if (val == 1)
182			note = Q_NOTIFY1;
183		else
184			note = 0;
185		break;
186	case (VIRTIO_MMIO_QUEUE_PFN):
187		note = Q_PFN;
188		break;
189	case (VIRTIO_MMIO_QUEUE_SEL):
190		note = Q_SEL;
191		break;
192	default:
193		note = 0;
194	}
195
196	if (note) {
197		mips_dcache_wbinv_all();
198
199		if (!sc->use_pio)
200			return (0);
201
202		PIO_SET(sc->pio_send, note, 1);
203
204		/*
205		 * Wait until host ack the request.
206		 * Usually done within few cycles.
207		 * TODO: bad
208		 */
209
210		for (i = 100; i > 0; i--) {
211			if (PIO_READ(sc->pio_send) == 0)
212				break;
213		}
214
215		if (i == 0)
216			device_printf(sc->dev, "Warning: host busy\n");
217	}
218
219	return (0);
220}
221
222static void
223platform_intr(void *arg)
224{
225	struct virtio_mmio_platform_softc *sc;
226	int reg;
227
228	sc = arg;
229
230	if (sc->use_pio) {
231		/* Read pending */
232		reg = PIO_READ(sc->pio_recv);
233
234		/* Ack */
235		PIO_SET(sc->pio_recv, reg, 0);
236	}
237
238	/* Writeback, invalidate cache */
239	mips_dcache_wbinv_all();
240
241	if (sc->intr_handler != NULL)
242		sc->intr_handler(sc->ih_user);
243}
244
245static int
246platform_setup_intr(device_t dev, device_t mmio_dev,
247			void *intr_handler, void *ih_user)
248{
249	struct virtio_mmio_platform_softc *sc;
250	int rid;
251
252	sc = device_get_softc(dev);
253
254	sc->intr_handler = intr_handler;
255	sc->ih_user = ih_user;
256
257	if (sc->use_pio) {
258		PIO_SETUP_IRQ(sc->pio_recv, platform_intr, sc);
259		return (0);
260	}
261
262	rid = 0;
263	sc->res[0] = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
264		RF_ACTIVE);
265	if (!sc->res[0]) {
266		device_printf(dev, "Can't allocate interrupt\n");
267		return (ENXIO);
268	}
269
270	if (bus_setup_intr(dev, sc->res[0], INTR_TYPE_MISC | INTR_MPSAFE,
271		NULL, platform_intr, sc, &sc->ih)) {
272		device_printf(dev, "Can't setup the interrupt\n");
273		return (ENXIO);
274	}
275
276	return (0);
277}
278
279static int
280platform_poll(device_t dev)
281{
282
283	mips_dcache_wbinv_all();
284
285	return (0);
286}
287
288static device_method_t virtio_mmio_platform_methods[] = {
289	DEVMETHOD(device_probe,		virtio_mmio_platform_probe),
290	DEVMETHOD(device_attach,	virtio_mmio_platform_attach),
291
292	/* virtio_mmio_if.h */
293	DEVMETHOD(virtio_mmio_prewrite,		platform_prewrite),
294	DEVMETHOD(virtio_mmio_note,		platform_note),
295	DEVMETHOD(virtio_mmio_poll,		platform_poll),
296	DEVMETHOD(virtio_mmio_setup_intr,	platform_setup_intr),
297	DEVMETHOD_END
298};
299
300static driver_t virtio_mmio_platform_driver = {
301	"virtio_mmio_platform",
302	virtio_mmio_platform_methods,
303	sizeof(struct virtio_mmio_platform_softc),
304};
305
306DRIVER_MODULE(virtio_mmio_platform, simplebus, virtio_mmio_platform_driver,
307    0, 0);
308