1 /*-
2 * Copyright (c) 2014 Ruslan Bukin <[email protected]>
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/cdefs.h>
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/bus.h>
39 #include <sys/kernel.h>
40 #include <sys/module.h>
41 #include <sys/malloc.h>
42 #include <sys/rman.h>
43 #include <sys/timeet.h>
44 #include <sys/timetc.h>
45 #include <sys/conf.h>
46 #include <sys/uio.h>
47 #include <sys/stat.h>
48 #include <sys/time.h>
49 #include <sys/event.h>
50 #include <sys/selinfo.h>
51
52 #include <dev/fdt/fdt_common.h>
53 #include <dev/ofw/openfirm.h>
54 #include <dev/ofw/ofw_bus.h>
55 #include <dev/ofw/ofw_bus_subr.h>
56
57 #include <machine/bus.h>
58 #include <machine/fdt.h>
59 #include <machine/cpu.h>
60 #include <machine/intr.h>
61
62 #define READ4(_sc, _reg) \
63 bus_read_4((_sc)->res[0], _reg)
64 #define WRITE4(_sc, _reg, _val) \
65 bus_write_4((_sc)->res[0], _reg, _val)
66
67 #define CDES_INT_EN (1 << 15)
68 #define CDES_CAUSE_MASK 0x3
69 #define CDES_CAUSE_SHIFT 13
70 #define DEVNAME_MAXLEN 256
71
72 typedef struct
73 {
74 uint16_t cdes;
75 uint16_t interrupt_level;
76 uint16_t in;
77 uint16_t out;
78 } control_reg_t;
79
80 struct beri_softc {
81 struct resource *res[3];
82 bus_space_tag_t bst;
83 bus_space_handle_t bsh;
84 struct cdev *cdev;
85 device_t dev;
86 void *read_ih;
87 void *write_ih;
88 struct selinfo beri_rsel;
89 struct mtx beri_mtx;
90 int opened;
91
92 char devname[DEVNAME_MAXLEN];
93 int control_read;
94 int control_write;
95 int data_read;
96 int data_write;
97 int data_size;
98 };
99
100 static struct resource_spec beri_spec[] = {
101 { SYS_RES_MEMORY, 0, RF_ACTIVE },
102 { SYS_RES_IRQ, 0, RF_ACTIVE },
103 { SYS_RES_IRQ, 1, RF_ACTIVE },
104 { -1, 0 }
105 };
106
107 static control_reg_t
get_control_reg(struct beri_softc * sc,int dir)108 get_control_reg(struct beri_softc *sc, int dir)
109 {
110 uint32_t offset;
111 uint16_t dst[4];
112 control_reg_t c;
113 uint16_t *cp;
114 int i;
115
116 cp = (uint16_t *)&c;
117
118 offset = dir ? sc->control_write : sc->control_read;
119 ((uint32_t *)dst)[0] = READ4(sc, offset);
120 ((uint32_t *)dst)[1] = READ4(sc, offset + 4);
121
122 for (i = 0; i < 4; i++)
123 cp[i] = dst[3 - i];
124
125 return (c);
126 }
127
128 static void
set_control_reg(struct beri_softc * sc,int dir,control_reg_t * c)129 set_control_reg(struct beri_softc *sc, int dir, control_reg_t *c)
130 {
131 uint32_t offset;
132 uint16_t src[4];
133 uint16_t *cp;
134 int i;
135
136 cp = (uint16_t *)c;
137
138 for (i = 0; i < 4; i++)
139 src[3 - i] = cp[i];
140
141 offset = dir ? sc->control_write : sc->control_read;
142 WRITE4(sc, offset + 0, ((uint32_t *)src)[0]);
143 WRITE4(sc, offset + 4, ((uint32_t *)src)[1]);
144 }
145
146 static int
get_stock(struct beri_softc * sc,int dir,control_reg_t * c)147 get_stock(struct beri_softc *sc, int dir, control_reg_t *c)
148 {
149 uint32_t fill;
150
151 fill = (c->in - c->out + sc->data_size) % sc->data_size;
152
153 if (dir)
154 return (sc->data_size - fill - 1);
155 else
156 return (fill);
157 }
158
159 static void
beri_intr_write(void * arg)160 beri_intr_write(void *arg)
161 {
162 struct beri_softc *sc;
163 control_reg_t c;
164
165 sc = arg;
166
167 c = get_control_reg(sc, 1);
168 if (c.cdes & CDES_INT_EN) {
169 c.cdes &= ~(CDES_INT_EN);
170 set_control_reg(sc, 1, &c);
171 }
172
173 mtx_lock(&sc->beri_mtx);
174 selwakeuppri(&sc->beri_rsel, PZERO + 1);
175 KNOTE_LOCKED(&sc->beri_rsel.si_note, 0);
176 mtx_unlock(&sc->beri_mtx);
177 }
178
179 static void
beri_intr_read(void * arg)180 beri_intr_read(void *arg)
181 {
182 struct beri_softc *sc;
183 control_reg_t c;
184
185 sc = arg;
186
187 c = get_control_reg(sc, 0);
188 if (c.cdes & CDES_INT_EN) {
189 c.cdes &= ~(CDES_INT_EN);
190 set_control_reg(sc, 0, &c);
191 }
192
193 mtx_lock(&sc->beri_mtx);
194 selwakeuppri(&sc->beri_rsel, PZERO + 1);
195 KNOTE_LOCKED(&sc->beri_rsel.si_note, 0);
196 mtx_unlock(&sc->beri_mtx);
197 }
198
199 static int
beri_open(struct cdev * dev,int flags __unused,int fmt __unused,struct thread * td __unused)200 beri_open(struct cdev *dev, int flags __unused,
201 int fmt __unused, struct thread *td __unused)
202 {
203 struct beri_softc *sc;
204 control_reg_t c;
205
206 sc = dev->si_drv1;
207
208 if (sc->opened)
209 return (1);
210
211 /* Setup interrupt handlers */
212 if (bus_setup_intr(sc->dev, sc->res[1], INTR_TYPE_BIO | INTR_MPSAFE,
213 NULL, beri_intr_read, sc, &sc->read_ih)) {
214 device_printf(sc->dev, "Unable to setup read intr\n");
215 return (1);
216 }
217 if (bus_setup_intr(sc->dev, sc->res[2], INTR_TYPE_BIO | INTR_MPSAFE,
218 NULL, beri_intr_write, sc, &sc->write_ih)) {
219 device_printf(sc->dev, "Unable to setup write intr\n");
220 return (1);
221 }
222
223 sc->opened = 1;
224
225 /* Clear write buffer */
226 c = get_control_reg(sc, 1);
227 c.in = c.out;
228 c.cdes = 0;
229 set_control_reg(sc, 1, &c);
230
231 /* Clear read buffer */
232 c = get_control_reg(sc, 0);
233 c.out = c.in;
234 c.cdes = 0;
235 set_control_reg(sc, 0, &c);
236
237 return (0);
238 }
239
240 static int
beri_close(struct cdev * dev,int flags __unused,int fmt __unused,struct thread * td __unused)241 beri_close(struct cdev *dev, int flags __unused,
242 int fmt __unused, struct thread *td __unused)
243 {
244 struct beri_softc *sc;
245
246 sc = dev->si_drv1;
247
248 if (sc->opened) {
249 sc->opened = 0;
250
251 /* Unsetup interrupt handlers */
252 bus_teardown_intr(sc->dev, sc->res[1], sc->read_ih);
253 bus_teardown_intr(sc->dev, sc->res[2], sc->write_ih);
254 }
255
256 return (0);
257 }
258
259 static int
beri_rdwr(struct cdev * dev,struct uio * uio,int ioflag)260 beri_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
261 {
262 struct beri_softc *sc;
263 uint32_t offset;
264 control_reg_t c;
265 uint16_t *ptr;
266 uint8_t *dst;
267 int stock;
268 int dir;
269 int amount;
270 int count;
271
272 sc = dev->si_drv1;
273
274 dir = uio->uio_rw ? 1 : 0;
275
276 c = get_control_reg(sc, dir);
277 stock = get_stock(sc, dir, &c);
278 if (stock < uio->uio_resid) {
279 device_printf(sc->dev, "Err: no data/space available\n");
280 return (1);
281 }
282
283 amount = uio->uio_resid;
284 ptr = dir ? &c.in : &c.out;
285 count = (sc->data_size - *ptr);
286
287 offset = dir ? sc->data_write : sc->data_read;
288 dst = (uint8_t *)(sc->bsh + offset);
289
290 if (amount <= count) {
291 uiomove(dst + *ptr, amount, uio);
292 } else {
293 uiomove(dst + *ptr, count, uio);
294 uiomove(dst, (amount - count), uio);
295 }
296
297 *ptr = (*ptr + amount) % sc->data_size;
298 set_control_reg(sc, dir, &c);
299
300 return (0);
301 }
302
303 static int
beri_kqread(struct knote * kn,long hint)304 beri_kqread(struct knote *kn, long hint)
305 {
306 struct beri_softc *sc;
307 control_reg_t c;
308 int stock;
309
310 sc = kn->kn_hook;
311
312 c = get_control_reg(sc, 0);
313 stock = get_stock(sc, 0, &c);
314 if (stock) {
315 kn->kn_data = stock;
316 return (1);
317 }
318
319 kn->kn_data = 0;
320
321 /* Wait at least one new byte in buffer */
322 c.interrupt_level = 1;
323
324 /* Enable interrupts */
325 c.cdes |= (CDES_INT_EN);
326 set_control_reg(sc, 0, &c);
327
328 return (0);
329 }
330
331 static int
beri_kqwrite(struct knote * kn,long hint)332 beri_kqwrite(struct knote *kn, long hint)
333 {
334 struct beri_softc *sc;
335 control_reg_t c;
336 int stock;
337
338 sc = kn->kn_hook;
339
340 c = get_control_reg(sc, 1);
341 stock = get_stock(sc, 1, &c);
342 if (stock) {
343 kn->kn_data = stock;
344 return (1);
345 }
346
347 kn->kn_data = 0;
348
349 /* Wait at least one free position in buffer */
350 c.interrupt_level = sc->data_size - 2;
351
352 /* Enable interrupts */
353 c.cdes |= (CDES_INT_EN);
354 set_control_reg(sc, 1, &c);
355
356 return (0);
357 }
358
359 static void
beri_kqdetach(struct knote * kn)360 beri_kqdetach(struct knote *kn)
361 {
362 struct beri_softc *sc;
363
364 sc = kn->kn_hook;
365
366 knlist_remove(&sc->beri_rsel.si_note, kn, 0);
367 }
368
369 static struct filterops beri_read_filterops = {
370 .f_isfd = 1,
371 .f_attach = NULL,
372 .f_detach = beri_kqdetach,
373 .f_event = beri_kqread,
374 };
375
376 static struct filterops beri_write_filterops = {
377 .f_isfd = 1,
378 .f_attach = NULL,
379 .f_detach = beri_kqdetach,
380 .f_event = beri_kqwrite,
381 };
382
383 static int
beri_kqfilter(struct cdev * dev,struct knote * kn)384 beri_kqfilter(struct cdev *dev, struct knote *kn)
385 {
386 struct beri_softc *sc;
387
388 sc = dev->si_drv1;
389
390 switch(kn->kn_filter) {
391 case EVFILT_READ:
392 kn->kn_fop = &beri_read_filterops;
393 break;
394 case EVFILT_WRITE:
395 kn->kn_fop = &beri_write_filterops;
396 break;
397 default:
398 return(EINVAL);
399 }
400
401 kn->kn_hook = sc;
402 knlist_add(&sc->beri_rsel.si_note, kn, 0);
403
404 return (0);
405 }
406
407 static struct cdevsw beri_cdevsw = {
408 .d_version = D_VERSION,
409 .d_open = beri_open,
410 .d_close = beri_close,
411 .d_write = beri_rdwr,
412 .d_read = beri_rdwr,
413 .d_kqfilter = beri_kqfilter,
414 .d_name = "beri ring buffer",
415 };
416
417 static int
parse_fdt(struct beri_softc * sc)418 parse_fdt(struct beri_softc *sc)
419 {
420 pcell_t dts_value[0];
421 phandle_t node;
422 int len;
423
424 if ((node = ofw_bus_get_node(sc->dev)) == -1)
425 return (ENXIO);
426
427 /* get device name */
428 if (OF_getprop(ofw_bus_get_node(sc->dev), "device_name",
429 &sc->devname, sizeof(sc->devname)) <= 0) {
430 device_printf(sc->dev, "Can't get device_name\n");
431 return (ENXIO);
432 }
433
434 if ((len = OF_getproplen(node, "data_size")) <= 0)
435 return (ENXIO);
436 OF_getencprop(node, "data_size", dts_value, len);
437 sc->data_size = dts_value[0];
438
439 if ((len = OF_getproplen(node, "data_read")) <= 0)
440 return (ENXIO);
441 OF_getencprop(node, "data_read", dts_value, len);
442 sc->data_read = dts_value[0];
443
444 if ((len = OF_getproplen(node, "data_write")) <= 0)
445 return (ENXIO);
446 OF_getencprop(node, "data_write", dts_value, len);
447 sc->data_write = dts_value[0];
448
449 if ((len = OF_getproplen(node, "control_read")) <= 0)
450 return (ENXIO);
451 OF_getencprop(node, "control_read", dts_value, len);
452 sc->control_read = dts_value[0];
453
454 if ((len = OF_getproplen(node, "control_write")) <= 0)
455 return (ENXIO);
456 OF_getencprop(node, "control_write", dts_value, len);
457 sc->control_write = dts_value[0];
458
459 return (0);
460 }
461
462 static int
beri_probe(device_t dev)463 beri_probe(device_t dev)
464 {
465
466 if (!ofw_bus_status_okay(dev))
467 return (ENXIO);
468
469 if (!ofw_bus_is_compatible(dev, "sri-cambridge,beri-ring"))
470 return (ENXIO);
471
472 device_set_desc(dev, "SRI-Cambridge BERI ring buffer");
473 return (BUS_PROBE_DEFAULT);
474 }
475
476 static int
beri_attach(device_t dev)477 beri_attach(device_t dev)
478 {
479 struct beri_softc *sc;
480
481 sc = device_get_softc(dev);
482 sc->dev = dev;
483
484 if (bus_alloc_resources(dev, beri_spec, sc->res)) {
485 device_printf(dev, "could not allocate resources\n");
486 return (ENXIO);
487 }
488
489 /* Memory interface */
490 sc->bst = rman_get_bustag(sc->res[0]);
491 sc->bsh = rman_get_bushandle(sc->res[0]);
492
493 if (parse_fdt(sc)) {
494 device_printf(sc->dev, "Can't get FDT values\n");
495 return (ENXIO);
496 }
497
498 sc->cdev = make_dev(&beri_cdevsw, 0, UID_ROOT, GID_WHEEL,
499 S_IRWXU, "%s", sc->devname);
500 if (sc->cdev == NULL) {
501 device_printf(dev, "Failed to create character device.\n");
502 return (ENXIO);
503 }
504
505 sc->cdev->si_drv1 = sc;
506
507 mtx_init(&sc->beri_mtx, "beri_mtx", NULL, MTX_DEF);
508 knlist_init_mtx(&sc->beri_rsel.si_note, &sc->beri_mtx);
509
510 return (0);
511 }
512
513 static device_method_t beri_methods[] = {
514 DEVMETHOD(device_probe, beri_probe),
515 DEVMETHOD(device_attach, beri_attach),
516 { 0, 0 }
517 };
518
519 static driver_t beri_driver = {
520 "beri_ring",
521 beri_methods,
522 sizeof(struct beri_softc),
523 };
524
525 DRIVER_MODULE(beri_ring, simplebus, beri_driver, 0, 0);
526