xref: /freebsd/sys/arm/arm/generic_timer.c (revision d93a896e)
1 /*-
2  * Copyright (c) 2011 The FreeBSD Foundation
3  * Copyright (c) 2013 Ruslan Bukin <br@bsdpad.com>
4  * All rights reserved.
5  *
6  * Based on mpcore_timer.c developed by Ben Gray <ben.r.gray@gmail.com>
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the company nor the name of the author may be used to
17  *    endorse or promote products derived from this software without specific
18  *    prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /**
34  *      Cortex-A7, Cortex-A15, ARMv8 and later Generic Timer
35  */
36 
37 #include "opt_acpi.h"
38 #include "opt_platform.h"
39 
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/bus.h>
46 #include <sys/kernel.h>
47 #include <sys/module.h>
48 #include <sys/malloc.h>
49 #include <sys/rman.h>
50 #include <sys/timeet.h>
51 #include <sys/timetc.h>
52 #include <sys/smp.h>
53 #include <sys/vdso.h>
54 #include <sys/watchdog.h>
55 #include <machine/bus.h>
56 #include <machine/cpu.h>
57 #include <machine/intr.h>
58 #include <machine/md_var.h>
59 
60 #if defined(__arm__)
61 #include <machine/machdep.h> /* For arm_set_delay */
62 #endif
63 
64 #ifdef FDT
65 #include <dev/ofw/openfirm.h>
66 #include <dev/ofw/ofw_bus.h>
67 #include <dev/ofw/ofw_bus_subr.h>
68 #endif
69 
70 #ifdef DEV_ACPI
71 #include <contrib/dev/acpica/include/acpi.h>
72 #include <dev/acpica/acpivar.h>
73 #endif
74 
75 #define	GT_CTRL_ENABLE		(1 << 0)
76 #define	GT_CTRL_INT_MASK	(1 << 1)
77 #define	GT_CTRL_INT_STAT	(1 << 2)
78 #define	GT_REG_CTRL		0
79 #define	GT_REG_TVAL		1
80 
81 #define	GT_CNTKCTL_PL0PTEN	(1 << 9) /* PL0 Physical timer reg access */
82 #define	GT_CNTKCTL_PL0VTEN	(1 << 8) /* PL0 Virtual timer reg access */
83 #define	GT_CNTKCTL_EVNTI	(0xf << 4) /* Virtual counter event bits */
84 #define	GT_CNTKCTL_EVNTDIR	(1 << 3) /* Virtual counter event transition */
85 #define	GT_CNTKCTL_EVNTEN	(1 << 2) /* Enables virtual counter events */
86 #define	GT_CNTKCTL_PL0VCTEN	(1 << 1) /* PL0 CNTVCT and CNTFRQ access */
87 #define	GT_CNTKCTL_PL0PCTEN	(1 << 0) /* PL0 CNTPCT and CNTFRQ access */
88 
89 struct arm_tmr_softc {
90 	struct resource		*res[4];
91 	void			*ihl[4];
92 	uint32_t		clkfreq;
93 	struct eventtimer	et;
94 	bool			physical;
95 };
96 
97 static struct arm_tmr_softc *arm_tmr_sc = NULL;
98 
99 static struct resource_spec timer_spec[] = {
100 	{ SYS_RES_IRQ,		0,	RF_ACTIVE },	/* Secure */
101 	{ SYS_RES_IRQ,		1,	RF_ACTIVE },	/* Non-secure */
102 	{ SYS_RES_IRQ,		2,	RF_ACTIVE | RF_OPTIONAL }, /* Virt */
103 	{ SYS_RES_IRQ,		3,	RF_ACTIVE | RF_OPTIONAL	}, /* Hyp */
104 	{ -1, 0 }
105 };
106 
107 static uint32_t arm_tmr_fill_vdso_timehands(struct vdso_timehands *vdso_th,
108     struct timecounter *tc);
109 static void arm_tmr_do_delay(int usec, void *);
110 
111 static timecounter_get_t arm_tmr_get_timecount;
112 
113 static struct timecounter arm_tmr_timecount = {
114 	.tc_name           = "ARM MPCore Timecounter",
115 	.tc_get_timecount  = arm_tmr_get_timecount,
116 	.tc_poll_pps       = NULL,
117 	.tc_counter_mask   = ~0u,
118 	.tc_frequency      = 0,
119 	.tc_quality        = 1000,
120 	.tc_fill_vdso_timehands = arm_tmr_fill_vdso_timehands,
121 };
122 
123 #ifdef __arm__
124 #define	get_el0(x)	cp15_## x ##_get()
125 #define	get_el1(x)	cp15_## x ##_get()
126 #define	set_el0(x, val)	cp15_## x ##_set(val)
127 #define	set_el1(x, val)	cp15_## x ##_set(val)
128 #else /* __aarch64__ */
129 #define	get_el0(x)	READ_SPECIALREG(x ##_el0)
130 #define	get_el1(x)	READ_SPECIALREG(x ##_el1)
131 #define	set_el0(x, val)	WRITE_SPECIALREG(x ##_el0, val)
132 #define	set_el1(x, val)	WRITE_SPECIALREG(x ##_el1, val)
133 #endif
134 
135 static int
136 get_freq(void)
137 {
138 	return (get_el0(cntfrq));
139 }
140 
141 static uint64_t
142 get_cntxct(bool physical)
143 {
144 	uint64_t val;
145 
146 	isb();
147 	if (physical)
148 		val = get_el0(cntpct);
149 	else
150 		val = get_el0(cntvct);
151 
152 	return (val);
153 }
154 
155 static int
156 set_ctrl(uint32_t val, bool physical)
157 {
158 
159 	if (physical)
160 		set_el0(cntp_ctl, val);
161 	else
162 		set_el0(cntv_ctl, val);
163 	isb();
164 
165 	return (0);
166 }
167 
168 static int
169 set_tval(uint32_t val, bool physical)
170 {
171 
172 	if (physical)
173 		set_el0(cntp_tval, val);
174 	else
175 		set_el0(cntv_tval, val);
176 	isb();
177 
178 	return (0);
179 }
180 
181 static int
182 get_ctrl(bool physical)
183 {
184 	uint32_t val;
185 
186 	if (physical)
187 		val = get_el0(cntp_ctl);
188 	else
189 		val = get_el0(cntv_ctl);
190 
191 	return (val);
192 }
193 
194 static void
195 setup_user_access(void *arg __unused)
196 {
197 	uint32_t cntkctl;
198 
199 	cntkctl = get_el1(cntkctl);
200 	cntkctl &= ~(GT_CNTKCTL_PL0PTEN | GT_CNTKCTL_PL0VTEN |
201 	    GT_CNTKCTL_EVNTEN);
202 	if (arm_tmr_sc->physical) {
203 		cntkctl |= GT_CNTKCTL_PL0PCTEN;
204 		cntkctl &= ~GT_CNTKCTL_PL0VCTEN;
205 	} else {
206 		cntkctl |= GT_CNTKCTL_PL0VCTEN;
207 		cntkctl &= ~GT_CNTKCTL_PL0PCTEN;
208 	}
209 	set_el1(cntkctl, cntkctl);
210 	isb();
211 }
212 
213 static void
214 tmr_setup_user_access(void *arg __unused)
215 {
216 
217 	if (arm_tmr_sc != NULL)
218 		smp_rendezvous(NULL, setup_user_access, NULL, NULL);
219 }
220 SYSINIT(tmr_ua, SI_SUB_SMP, SI_ORDER_SECOND, tmr_setup_user_access, NULL);
221 
222 static unsigned
223 arm_tmr_get_timecount(struct timecounter *tc)
224 {
225 
226 	return (get_cntxct(arm_tmr_sc->physical));
227 }
228 
229 static int
230 arm_tmr_start(struct eventtimer *et, sbintime_t first,
231     sbintime_t period __unused)
232 {
233 	struct arm_tmr_softc *sc;
234 	int counts, ctrl;
235 
236 	sc = (struct arm_tmr_softc *)et->et_priv;
237 
238 	if (first != 0) {
239 		counts = ((uint32_t)et->et_frequency * first) >> 32;
240 		ctrl = get_ctrl(sc->physical);
241 		ctrl &= ~GT_CTRL_INT_MASK;
242 		ctrl |= GT_CTRL_ENABLE;
243 		set_tval(counts, sc->physical);
244 		set_ctrl(ctrl, sc->physical);
245 		return (0);
246 	}
247 
248 	return (EINVAL);
249 
250 }
251 
252 static int
253 arm_tmr_stop(struct eventtimer *et)
254 {
255 	struct arm_tmr_softc *sc;
256 	int ctrl;
257 
258 	sc = (struct arm_tmr_softc *)et->et_priv;
259 
260 	ctrl = get_ctrl(sc->physical);
261 	ctrl &= ~GT_CTRL_ENABLE;
262 	set_ctrl(ctrl, sc->physical);
263 
264 	return (0);
265 }
266 
267 static int
268 arm_tmr_intr(void *arg)
269 {
270 	struct arm_tmr_softc *sc;
271 	int ctrl;
272 
273 	sc = (struct arm_tmr_softc *)arg;
274 	ctrl = get_ctrl(sc->physical);
275 	if (ctrl & GT_CTRL_INT_STAT) {
276 		ctrl |= GT_CTRL_INT_MASK;
277 		set_ctrl(ctrl, sc->physical);
278 	}
279 
280 	if (sc->et.et_active)
281 		sc->et.et_event_cb(&sc->et, sc->et.et_arg);
282 
283 	return (FILTER_HANDLED);
284 }
285 
286 #ifdef FDT
287 static int
288 arm_tmr_fdt_probe(device_t dev)
289 {
290 
291 	if (!ofw_bus_status_okay(dev))
292 		return (ENXIO);
293 
294 	if (ofw_bus_is_compatible(dev, "arm,armv7-timer")) {
295 		device_set_desc(dev, "ARMv7 Generic Timer");
296 		return (BUS_PROBE_DEFAULT);
297 	} else if (ofw_bus_is_compatible(dev, "arm,armv8-timer")) {
298 		device_set_desc(dev, "ARMv8 Generic Timer");
299 		return (BUS_PROBE_DEFAULT);
300 	}
301 
302 	return (ENXIO);
303 }
304 #endif
305 
306 #ifdef DEV_ACPI
307 static void
308 arm_tmr_acpi_identify(driver_t *driver, device_t parent)
309 {
310 	ACPI_TABLE_GTDT *gtdt;
311 	vm_paddr_t physaddr;
312 	device_t dev;
313 
314 	physaddr = acpi_find_table(ACPI_SIG_GTDT);
315 	if (physaddr == 0)
316 		return;
317 
318 	gtdt = acpi_map_table(physaddr, ACPI_SIG_GTDT);
319 	if (gtdt == NULL) {
320 		device_printf(parent, "gic: Unable to map the GTDT\n");
321 		return;
322 	}
323 
324 	dev = BUS_ADD_CHILD(parent, BUS_PASS_TIMER + BUS_PASS_ORDER_MIDDLE,
325 	    "generic_timer", -1);
326 	if (dev == NULL) {
327 		device_printf(parent, "add gic child failed\n");
328 		goto out;
329 	}
330 
331 	BUS_SET_RESOURCE(parent, dev, SYS_RES_IRQ, 0,
332 	    gtdt->SecureEl1Interrupt, 1);
333 	BUS_SET_RESOURCE(parent, dev, SYS_RES_IRQ, 1,
334 	    gtdt->NonSecureEl1Interrupt, 1);
335 	BUS_SET_RESOURCE(parent, dev, SYS_RES_IRQ, 2,
336 	    gtdt->VirtualTimerInterrupt, 1);
337 
338 out:
339 	acpi_unmap_table(gtdt);
340 }
341 
342 static int
343 arm_tmr_acpi_probe(device_t dev)
344 {
345 
346 	device_set_desc(dev, "ARM Generic Timer");
347 	return (BUS_PROBE_NOWILDCARD);
348 }
349 #endif
350 
351 
352 static int
353 arm_tmr_attach(device_t dev)
354 {
355 	struct arm_tmr_softc *sc;
356 #ifdef FDT
357 	phandle_t node;
358 	pcell_t clock;
359 #endif
360 	int error;
361 	int i;
362 
363 	sc = device_get_softc(dev);
364 	if (arm_tmr_sc)
365 		return (ENXIO);
366 
367 #ifdef FDT
368 	/* Get the base clock frequency */
369 	node = ofw_bus_get_node(dev);
370 	if (node > 0) {
371 		error = OF_getencprop(node, "clock-frequency", &clock,
372 		    sizeof(clock));
373 		if (error > 0)
374 			sc->clkfreq = clock;
375 	}
376 #endif
377 
378 	if (sc->clkfreq == 0) {
379 		/* Try to get clock frequency from timer */
380 		sc->clkfreq = get_freq();
381 	}
382 
383 	if (sc->clkfreq == 0) {
384 		device_printf(dev, "No clock frequency specified\n");
385 		return (ENXIO);
386 	}
387 
388 	if (bus_alloc_resources(dev, timer_spec, sc->res)) {
389 		device_printf(dev, "could not allocate resources\n");
390 		return (ENXIO);
391 	}
392 
393 #ifdef __arm__
394 	sc->physical = true;
395 #else /* __aarch64__ */
396 	/* If we do not have a virtual timer use the physical. */
397 	sc->physical = (sc->res[2] == NULL) ? true : false;
398 #endif
399 
400 	arm_tmr_sc = sc;
401 
402 	/* Setup secure, non-secure and virtual IRQs handler */
403 	for (i = 0; i < 3; i++) {
404 		/* If we do not have the interrupt, skip it. */
405 		if (sc->res[i] == NULL)
406 			continue;
407 		error = bus_setup_intr(dev, sc->res[i], INTR_TYPE_CLK,
408 		    arm_tmr_intr, NULL, sc, &sc->ihl[i]);
409 		if (error) {
410 			device_printf(dev, "Unable to alloc int resource.\n");
411 			return (ENXIO);
412 		}
413 	}
414 
415 	arm_tmr_timecount.tc_frequency = sc->clkfreq;
416 	tc_init(&arm_tmr_timecount);
417 
418 	sc->et.et_name = "ARM MPCore Eventtimer";
419 	sc->et.et_flags = ET_FLAGS_ONESHOT | ET_FLAGS_PERCPU;
420 	sc->et.et_quality = 1000;
421 
422 	sc->et.et_frequency = sc->clkfreq;
423 	sc->et.et_min_period = (0x00000010LLU << 32) / sc->et.et_frequency;
424 	sc->et.et_max_period = (0xfffffffeLLU << 32) / sc->et.et_frequency;
425 	sc->et.et_start = arm_tmr_start;
426 	sc->et.et_stop = arm_tmr_stop;
427 	sc->et.et_priv = sc;
428 	et_register(&sc->et);
429 
430 #if defined(__arm__)
431 	arm_set_delay(arm_tmr_do_delay, sc);
432 #endif
433 
434 	return (0);
435 }
436 
437 #ifdef FDT
438 static device_method_t arm_tmr_fdt_methods[] = {
439 	DEVMETHOD(device_probe,		arm_tmr_fdt_probe),
440 	DEVMETHOD(device_attach,	arm_tmr_attach),
441 	{ 0, 0 }
442 };
443 
444 static driver_t arm_tmr_fdt_driver = {
445 	"generic_timer",
446 	arm_tmr_fdt_methods,
447 	sizeof(struct arm_tmr_softc),
448 };
449 
450 static devclass_t arm_tmr_fdt_devclass;
451 
452 EARLY_DRIVER_MODULE(timer, simplebus, arm_tmr_fdt_driver, arm_tmr_fdt_devclass,
453     0, 0, BUS_PASS_TIMER + BUS_PASS_ORDER_MIDDLE);
454 EARLY_DRIVER_MODULE(timer, ofwbus, arm_tmr_fdt_driver, arm_tmr_fdt_devclass,
455     0, 0, BUS_PASS_TIMER + BUS_PASS_ORDER_MIDDLE);
456 #endif
457 
458 #ifdef DEV_ACPI
459 static device_method_t arm_tmr_acpi_methods[] = {
460 	DEVMETHOD(device_identify,	arm_tmr_acpi_identify),
461 	DEVMETHOD(device_probe,		arm_tmr_acpi_probe),
462 	DEVMETHOD(device_attach,	arm_tmr_attach),
463 	{ 0, 0 }
464 };
465 
466 static driver_t arm_tmr_acpi_driver = {
467 	"generic_timer",
468 	arm_tmr_acpi_methods,
469 	sizeof(struct arm_tmr_softc),
470 };
471 
472 static devclass_t arm_tmr_acpi_devclass;
473 
474 EARLY_DRIVER_MODULE(timer, acpi, arm_tmr_acpi_driver, arm_tmr_acpi_devclass,
475     0, 0, BUS_PASS_TIMER + BUS_PASS_ORDER_MIDDLE);
476 #endif
477 
478 static void
479 arm_tmr_do_delay(int usec, void *arg)
480 {
481 	struct arm_tmr_softc *sc = arg;
482 	int32_t counts, counts_per_usec;
483 	uint32_t first, last;
484 
485 	/* Get the number of times to count */
486 	counts_per_usec = ((arm_tmr_timecount.tc_frequency / 1000000) + 1);
487 
488 	/*
489 	 * Clamp the timeout at a maximum value (about 32 seconds with
490 	 * a 66MHz clock). *Nobody* should be delay()ing for anywhere
491 	 * near that length of time and if they are, they should be hung
492 	 * out to dry.
493 	 */
494 	if (usec >= (0x80000000U / counts_per_usec))
495 		counts = (0x80000000U / counts_per_usec) - 1;
496 	else
497 		counts = usec * counts_per_usec;
498 
499 	first = get_cntxct(sc->physical);
500 
501 	while (counts > 0) {
502 		last = get_cntxct(sc->physical);
503 		counts -= (int32_t)(last - first);
504 		first = last;
505 	}
506 }
507 
508 #if defined(__aarch64__)
509 void
510 DELAY(int usec)
511 {
512 	int32_t counts;
513 
514 	/*
515 	 * Check the timers are setup, if not just
516 	 * use a for loop for the meantime
517 	 */
518 	if (arm_tmr_sc == NULL) {
519 		for (; usec > 0; usec--)
520 			for (counts = 200; counts > 0; counts--)
521 				/*
522 				 * Prevent the compiler from optimizing
523 				 * out the loop
524 				 */
525 				cpufunc_nullop();
526 	} else
527 		arm_tmr_do_delay(usec, arm_tmr_sc);
528 }
529 #endif
530 
531 static uint32_t
532 arm_tmr_fill_vdso_timehands(struct vdso_timehands *vdso_th,
533     struct timecounter *tc)
534 {
535 
536 	vdso_th->th_algo = VDSO_TH_ALGO_ARM_GENTIM;
537 	vdso_th->th_physical = arm_tmr_sc->physical;
538 	bzero(vdso_th->th_res, sizeof(vdso_th->th_res));
539 	return (1);
540 }
541