1 /*-
2 * Copyright (c) 2014 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 * SRI-Cambridge BERI soft processor <-> ARM core ring buffer.
33 */
34
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 #include <sys/kernel.h>
39 #include <sys/module.h>
40 #include <sys/malloc.h>
41 #include <sys/rman.h>
42 #include <sys/timeet.h>
43 #include <sys/timetc.h>
44 #include <sys/conf.h>
45 #include <sys/uio.h>
46 #include <sys/stat.h>
47 #include <sys/time.h>
48 #include <sys/event.h>
49 #include <sys/selinfo.h>
50
51 #include <dev/fdt/fdt_common.h>
52 #include <dev/ofw/openfirm.h>
53 #include <dev/ofw/ofw_bus.h>
54 #include <dev/ofw/ofw_bus_subr.h>
55
56 #include <machine/bus.h>
57 #include <machine/fdt.h>
58 #include <machine/cpu.h>
59 #include <machine/intr.h>
60
61 #define READ4(_sc, _reg) \
62 bus_read_4((_sc)->res[0], _reg)
63 #define WRITE4(_sc, _reg, _val) \
64 bus_write_4((_sc)->res[0], _reg, _val)
65
66 #define CDES_INT_EN (1 << 15)
67 #define CDES_CAUSE_MASK 0x3
68 #define CDES_CAUSE_SHIFT 13
69 #define DEVNAME_MAXLEN 256
70
71 typedef struct
72 {
73 uint16_t cdes;
74 uint16_t interrupt_level;
75 uint16_t in;
76 uint16_t out;
77 } control_reg_t;
78
79 struct beri_softc {
80 struct resource *res[3];
81 bus_space_tag_t bst;
82 bus_space_handle_t bsh;
83 struct cdev *cdev;
84 device_t dev;
85 void *read_ih;
86 void *write_ih;
87 struct selinfo beri_rsel;
88 struct mtx beri_mtx;
89 int opened;
90
91 char devname[DEVNAME_MAXLEN];
92 int control_read;
93 int control_write;
94 int data_read;
95 int data_write;
96 int data_size;
97 };
98
99 static struct resource_spec beri_spec[] = {
100 { SYS_RES_MEMORY, 0, RF_ACTIVE },
101 { SYS_RES_IRQ, 0, RF_ACTIVE },
102 { SYS_RES_IRQ, 1, RF_ACTIVE },
103 { -1, 0 }
104 };
105
106 static control_reg_t
get_control_reg(struct beri_softc * sc,int dir)107 get_control_reg(struct beri_softc *sc, int dir)
108 {
109 uint32_t offset;
110 uint16_t dst[4];
111 control_reg_t c;
112 uint16_t *cp;
113 int i;
114
115 cp = (uint16_t *)&c;
116
117 offset = dir ? sc->control_write : sc->control_read;
118 ((uint32_t *)dst)[0] = READ4(sc, offset);
119 ((uint32_t *)dst)[1] = READ4(sc, offset + 4);
120
121 for (i = 0; i < 4; i++)
122 cp[i] = dst[3 - i];
123
124 return (c);
125 }
126
127 static void
set_control_reg(struct beri_softc * sc,int dir,control_reg_t * c)128 set_control_reg(struct beri_softc *sc, int dir, control_reg_t *c)
129 {
130 uint32_t offset;
131 uint16_t src[4];
132 uint16_t *cp;
133 int i;
134
135 cp = (uint16_t *)c;
136
137 for (i = 0; i < 4; i++)
138 src[3 - i] = cp[i];
139
140 offset = dir ? sc->control_write : sc->control_read;
141 WRITE4(sc, offset + 0, ((uint32_t *)src)[0]);
142 WRITE4(sc, offset + 4, ((uint32_t *)src)[1]);
143 }
144
145 static int
get_stock(struct beri_softc * sc,int dir,control_reg_t * c)146 get_stock(struct beri_softc *sc, int dir, control_reg_t *c)
147 {
148 uint32_t fill;
149
150 fill = (c->in - c->out + sc->data_size) % sc->data_size;
151
152 if (dir)
153 return (sc->data_size - fill - 1);
154 else
155 return (fill);
156 }
157
158 static void
beri_intr_write(void * arg)159 beri_intr_write(void *arg)
160 {
161 struct beri_softc *sc;
162 control_reg_t c;
163
164 sc = arg;
165
166 c = get_control_reg(sc, 1);
167 if (c.cdes & CDES_INT_EN) {
168 c.cdes &= ~(CDES_INT_EN);
169 set_control_reg(sc, 1, &c);
170 }
171
172 mtx_lock(&sc->beri_mtx);
173 selwakeuppri(&sc->beri_rsel, PZERO + 1);
174 KNOTE_LOCKED(&sc->beri_rsel.si_note, 0);
175 mtx_unlock(&sc->beri_mtx);
176 }
177
178 static void
beri_intr_read(void * arg)179 beri_intr_read(void *arg)
180 {
181 struct beri_softc *sc;
182 control_reg_t c;
183
184 sc = arg;
185
186 c = get_control_reg(sc, 0);
187 if (c.cdes & CDES_INT_EN) {
188 c.cdes &= ~(CDES_INT_EN);
189 set_control_reg(sc, 0, &c);
190 }
191
192 mtx_lock(&sc->beri_mtx);
193 selwakeuppri(&sc->beri_rsel, PZERO + 1);
194 KNOTE_LOCKED(&sc->beri_rsel.si_note, 0);
195 mtx_unlock(&sc->beri_mtx);
196 }
197
198 static int
beri_open(struct cdev * dev,int flags __unused,int fmt __unused,struct thread * td __unused)199 beri_open(struct cdev *dev, int flags __unused,
200 int fmt __unused, struct thread *td __unused)
201 {
202 struct beri_softc *sc;
203 control_reg_t c;
204
205 sc = dev->si_drv1;
206
207 if (sc->opened)
208 return (1);
209
210 /* Setup interrupt handlers */
211 if (bus_setup_intr(sc->dev, sc->res[1], INTR_TYPE_BIO | INTR_MPSAFE,
212 NULL, beri_intr_read, sc, &sc->read_ih)) {
213 device_printf(sc->dev, "Unable to setup read intr\n");
214 return (1);
215 }
216 if (bus_setup_intr(sc->dev, sc->res[2], INTR_TYPE_BIO | INTR_MPSAFE,
217 NULL, beri_intr_write, sc, &sc->write_ih)) {
218 device_printf(sc->dev, "Unable to setup write intr\n");
219 return (1);
220 }
221
222 sc->opened = 1;
223
224 /* Clear write buffer */
225 c = get_control_reg(sc, 1);
226 c.in = c.out;
227 c.cdes = 0;
228 set_control_reg(sc, 1, &c);
229
230 /* Clear read buffer */
231 c = get_control_reg(sc, 0);
232 c.out = c.in;
233 c.cdes = 0;
234 set_control_reg(sc, 0, &c);
235
236 return (0);
237 }
238
239 static int
beri_close(struct cdev * dev,int flags __unused,int fmt __unused,struct thread * td __unused)240 beri_close(struct cdev *dev, int flags __unused,
241 int fmt __unused, struct thread *td __unused)
242 {
243 struct beri_softc *sc;
244
245 sc = dev->si_drv1;
246
247 if (sc->opened) {
248 sc->opened = 0;
249
250 /* Unsetup interrupt handlers */
251 bus_teardown_intr(sc->dev, sc->res[1], sc->read_ih);
252 bus_teardown_intr(sc->dev, sc->res[2], sc->write_ih);
253 }
254
255 return (0);
256 }
257
258 static int
beri_rdwr(struct cdev * dev,struct uio * uio,int ioflag)259 beri_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
260 {
261 struct beri_softc *sc;
262 uint32_t offset;
263 control_reg_t c;
264 uint16_t *ptr;
265 uint8_t *dst;
266 int stock;
267 int dir;
268 int amount;
269 int count;
270
271 sc = dev->si_drv1;
272
273 dir = uio->uio_rw ? 1 : 0;
274
275 c = get_control_reg(sc, dir);
276 stock = get_stock(sc, dir, &c);
277 if (stock < uio->uio_resid) {
278 device_printf(sc->dev, "Err: no data/space available\n");
279 return (1);
280 }
281
282 amount = uio->uio_resid;
283 ptr = dir ? &c.in : &c.out;
284 count = (sc->data_size - *ptr);
285
286 offset = dir ? sc->data_write : sc->data_read;
287 dst = (uint8_t *)(sc->bsh + offset);
288
289 if (amount <= count) {
290 uiomove(dst + *ptr, amount, uio);
291 } else {
292 uiomove(dst + *ptr, count, uio);
293 uiomove(dst, (amount - count), uio);
294 }
295
296 *ptr = (*ptr + amount) % sc->data_size;
297 set_control_reg(sc, dir, &c);
298
299 return (0);
300 }
301
302 static int
beri_kqread(struct knote * kn,long hint)303 beri_kqread(struct knote *kn, long hint)
304 {
305 struct beri_softc *sc;
306 control_reg_t c;
307 int stock;
308
309 sc = kn->kn_hook;
310
311 c = get_control_reg(sc, 0);
312 stock = get_stock(sc, 0, &c);
313 if (stock) {
314 kn->kn_data = stock;
315 return (1);
316 }
317
318 kn->kn_data = 0;
319
320 /* Wait at least one new byte in buffer */
321 c.interrupt_level = 1;
322
323 /* Enable interrupts */
324 c.cdes |= (CDES_INT_EN);
325 set_control_reg(sc, 0, &c);
326
327 return (0);
328 }
329
330 static int
beri_kqwrite(struct knote * kn,long hint)331 beri_kqwrite(struct knote *kn, long hint)
332 {
333 struct beri_softc *sc;
334 control_reg_t c;
335 int stock;
336
337 sc = kn->kn_hook;
338
339 c = get_control_reg(sc, 1);
340 stock = get_stock(sc, 1, &c);
341 if (stock) {
342 kn->kn_data = stock;
343 return (1);
344 }
345
346 kn->kn_data = 0;
347
348 /* Wait at least one free position in buffer */
349 c.interrupt_level = sc->data_size - 2;
350
351 /* Enable interrupts */
352 c.cdes |= (CDES_INT_EN);
353 set_control_reg(sc, 1, &c);
354
355 return (0);
356 }
357
358 static void
beri_kqdetach(struct knote * kn)359 beri_kqdetach(struct knote *kn)
360 {
361 struct beri_softc *sc;
362
363 sc = kn->kn_hook;
364
365 knlist_remove(&sc->beri_rsel.si_note, kn, 0);
366 }
367
368 static const struct filterops beri_read_filterops = {
369 .f_isfd = 1,
370 .f_attach = NULL,
371 .f_detach = beri_kqdetach,
372 .f_event = beri_kqread,
373 };
374
375 static const struct filterops beri_write_filterops = {
376 .f_isfd = 1,
377 .f_attach = NULL,
378 .f_detach = beri_kqdetach,
379 .f_event = beri_kqwrite,
380 };
381
382 static int
beri_kqfilter(struct cdev * dev,struct knote * kn)383 beri_kqfilter(struct cdev *dev, struct knote *kn)
384 {
385 struct beri_softc *sc;
386
387 sc = dev->si_drv1;
388
389 switch(kn->kn_filter) {
390 case EVFILT_READ:
391 kn->kn_fop = &beri_read_filterops;
392 break;
393 case EVFILT_WRITE:
394 kn->kn_fop = &beri_write_filterops;
395 break;
396 default:
397 return(EINVAL);
398 }
399
400 kn->kn_hook = sc;
401 knlist_add(&sc->beri_rsel.si_note, kn, 0);
402
403 return (0);
404 }
405
406 static struct cdevsw beri_cdevsw = {
407 .d_version = D_VERSION,
408 .d_open = beri_open,
409 .d_close = beri_close,
410 .d_write = beri_rdwr,
411 .d_read = beri_rdwr,
412 .d_kqfilter = beri_kqfilter,
413 .d_name = "beri ring buffer",
414 };
415
416 static int
parse_fdt(struct beri_softc * sc)417 parse_fdt(struct beri_softc *sc)
418 {
419 pcell_t dts_value[0];
420 phandle_t node;
421 int len;
422
423 if ((node = ofw_bus_get_node(sc->dev)) == -1)
424 return (ENXIO);
425
426 /* get device name */
427 if (OF_getprop(ofw_bus_get_node(sc->dev), "device_name",
428 &sc->devname, sizeof(sc->devname)) <= 0) {
429 device_printf(sc->dev, "Can't get device_name\n");
430 return (ENXIO);
431 }
432
433 if ((len = OF_getproplen(node, "data_size")) <= 0)
434 return (ENXIO);
435 OF_getencprop(node, "data_size", dts_value, len);
436 sc->data_size = dts_value[0];
437
438 if ((len = OF_getproplen(node, "data_read")) <= 0)
439 return (ENXIO);
440 OF_getencprop(node, "data_read", dts_value, len);
441 sc->data_read = dts_value[0];
442
443 if ((len = OF_getproplen(node, "data_write")) <= 0)
444 return (ENXIO);
445 OF_getencprop(node, "data_write", dts_value, len);
446 sc->data_write = dts_value[0];
447
448 if ((len = OF_getproplen(node, "control_read")) <= 0)
449 return (ENXIO);
450 OF_getencprop(node, "control_read", dts_value, len);
451 sc->control_read = dts_value[0];
452
453 if ((len = OF_getproplen(node, "control_write")) <= 0)
454 return (ENXIO);
455 OF_getencprop(node, "control_write", dts_value, len);
456 sc->control_write = dts_value[0];
457
458 return (0);
459 }
460
461 static int
beri_probe(device_t dev)462 beri_probe(device_t dev)
463 {
464
465 if (!ofw_bus_status_okay(dev))
466 return (ENXIO);
467
468 if (!ofw_bus_is_compatible(dev, "sri-cambridge,beri-ring"))
469 return (ENXIO);
470
471 device_set_desc(dev, "SRI-Cambridge BERI ring buffer");
472 return (BUS_PROBE_DEFAULT);
473 }
474
475 static int
beri_attach(device_t dev)476 beri_attach(device_t dev)
477 {
478 struct beri_softc *sc;
479
480 sc = device_get_softc(dev);
481 sc->dev = dev;
482
483 if (bus_alloc_resources(dev, beri_spec, sc->res)) {
484 device_printf(dev, "could not allocate resources\n");
485 return (ENXIO);
486 }
487
488 /* Memory interface */
489 sc->bst = rman_get_bustag(sc->res[0]);
490 sc->bsh = rman_get_bushandle(sc->res[0]);
491
492 if (parse_fdt(sc)) {
493 device_printf(sc->dev, "Can't get FDT values\n");
494 return (ENXIO);
495 }
496
497 sc->cdev = make_dev(&beri_cdevsw, 0, UID_ROOT, GID_WHEEL,
498 S_IRWXU, "%s", sc->devname);
499 if (sc->cdev == NULL) {
500 device_printf(dev, "Failed to create character device.\n");
501 return (ENXIO);
502 }
503
504 sc->cdev->si_drv1 = sc;
505
506 mtx_init(&sc->beri_mtx, "beri_mtx", NULL, MTX_DEF);
507 knlist_init_mtx(&sc->beri_rsel.si_note, &sc->beri_mtx);
508
509 return (0);
510 }
511
512 static device_method_t beri_methods[] = {
513 DEVMETHOD(device_probe, beri_probe),
514 DEVMETHOD(device_attach, beri_attach),
515 { 0, 0 }
516 };
517
518 static driver_t beri_driver = {
519 "beri_ring",
520 beri_methods,
521 sizeof(struct beri_softc),
522 };
523
524 DRIVER_MODULE(beri_ring, simplebus, beri_driver, 0, 0);
525