1/*-
2 * Copyright (c) 2014 Robin Randhawa
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 */
27
28/*
29 * This implements support for ARM's Power State Co-ordination Interface
30 * [PSCI]. The implementation adheres to version 0.2 of the PSCI specification
31 * but also supports v0.1. PSCI standardizes operations such as system reset, CPU
32 * on/off/suspend. PSCI requires a compliant firmware implementation.
33 *
34 * The PSCI specification used for this implementation is available at:
35 *
36 * <http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0022b/index.html>.
37 *
38 * TODO:
39 * - Add support for remaining PSCI calls [this implementation only
40 *   supports get_version, system_reset and cpu_on].
41 */
42
43#include <sys/cdefs.h>
44__FBSDID("$FreeBSD$");
45
46#include "opt_acpi.h"
47#include "opt_platform.h"
48
49#include <sys/param.h>
50#include <sys/systm.h>
51#include <sys/bus.h>
52#include <sys/eventhandler.h>
53#include <sys/kernel.h>
54#include <sys/module.h>
55#include <sys/reboot.h>
56
57#include <machine/bus.h>
58#include <machine/machdep.h>
59
60#ifdef DEV_ACPI
61#include <contrib/dev/acpica/include/acpi.h>
62#include <dev/acpica/acpivar.h>
63#endif
64
65#ifdef FDT
66#include <dev/fdt/fdt_common.h>
67#include <dev/ofw/openfirm.h>
68#include <dev/ofw/ofw_bus.h>
69#include <dev/ofw/ofw_bus_subr.h>
70#endif
71
72#include <dev/psci/psci.h>
73
74struct psci_softc {
75	device_t        dev;
76
77	uint32_t	psci_version;
78	uint32_t	psci_fnids[PSCI_FN_MAX];
79};
80
81#ifdef FDT
82static int psci_v0_1_init(device_t dev, int default_version);
83#endif
84static int psci_v0_2_init(device_t dev, int default_version);
85
86struct psci_softc *psci_softc = NULL;
87
88#ifdef __arm__
89#define	USE_ACPI	0
90#define	USE_FDT		1
91#elif defined(__aarch64__)
92#define	USE_ACPI	(arm64_bus_method == ARM64_BUS_ACPI)
93#define	USE_FDT		(arm64_bus_method == ARM64_BUS_FDT)
94#else
95#error Unknown architecture
96#endif
97
98#ifdef FDT
99struct psci_init_def {
100	int		default_version;
101	psci_initfn_t	psci_init;
102};
103
104static struct psci_init_def psci_v1_0_init_def = {
105	.default_version = (1 << 16) | 0,
106	.psci_init = psci_v0_2_init
107};
108
109static struct psci_init_def psci_v0_2_init_def = {
110	.default_version = (0 << 16) | 2,
111	.psci_init = psci_v0_2_init
112};
113
114static struct psci_init_def psci_v0_1_init_def = {
115	.default_version = (0 << 16) | 1,
116	.psci_init = psci_v0_1_init
117};
118
119static struct ofw_compat_data compat_data[] = {
120	{"arm,psci-1.0",        (uintptr_t)&psci_v1_0_init_def},
121	{"arm,psci-0.2",        (uintptr_t)&psci_v0_2_init_def},
122	{"arm,psci",            (uintptr_t)&psci_v0_1_init_def},
123	{NULL,                  0}
124};
125#endif
126
127static int psci_attach(device_t, psci_initfn_t, int);
128static void psci_shutdown(void *, int);
129
130static int psci_find_callfn(psci_callfn_t *);
131static int psci_def_callfn(register_t, register_t, register_t, register_t);
132
133psci_callfn_t psci_callfn = psci_def_callfn;
134
135static void
136psci_init(void *dummy)
137{
138	psci_callfn_t new_callfn;
139
140	if (psci_find_callfn(&new_callfn) != PSCI_RETVAL_SUCCESS) {
141		printf("No PSCI/SMCCC call function found\n");
142		return;
143	}
144
145	psci_callfn = new_callfn;
146}
147/* This needs to be before cpu_mp at SI_SUB_CPU, SI_ORDER_THIRD */
148SYSINIT(psci_start, SI_SUB_CPU, SI_ORDER_FIRST, psci_init, NULL);
149
150static int
151psci_def_callfn(register_t a __unused, register_t b __unused,
152    register_t c __unused, register_t d __unused)
153{
154
155	panic("No PSCI/SMCCC call function set");
156}
157
158#ifdef FDT
159static int psci_fdt_probe(device_t dev);
160static int psci_fdt_attach(device_t dev);
161
162static device_method_t psci_fdt_methods[] = {
163	DEVMETHOD(device_probe,     psci_fdt_probe),
164	DEVMETHOD(device_attach,    psci_fdt_attach),
165
166	DEVMETHOD_END
167};
168
169static driver_t psci_fdt_driver = {
170	"psci",
171	psci_fdt_methods,
172	sizeof(struct psci_softc),
173};
174
175static devclass_t psci_fdt_devclass;
176
177EARLY_DRIVER_MODULE(psci, simplebus, psci_fdt_driver, psci_fdt_devclass, 0, 0,
178    BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);
179EARLY_DRIVER_MODULE(psci, ofwbus, psci_fdt_driver, psci_fdt_devclass, 0, 0,
180    BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);
181
182static psci_callfn_t
183psci_fdt_get_callfn(phandle_t node)
184{
185	char method[16];
186
187	if ((OF_getprop(node, "method", method, sizeof(method))) > 0) {
188		if (strcmp(method, "hvc") == 0)
189			return (psci_hvc_despatch);
190		else if (strcmp(method, "smc") == 0)
191			return (psci_smc_despatch);
192		else
193			printf("psci: PSCI conduit \"%s\" invalid\n", method);
194	} else
195		printf("psci: PSCI conduit not supplied in the device tree\n");
196
197	return (NULL);
198}
199
200static int
201psci_fdt_probe(device_t dev)
202{
203	const struct ofw_compat_data *ocd;
204
205	if (!ofw_bus_status_okay(dev))
206		return (ENXIO);
207
208	ocd = ofw_bus_search_compatible(dev, compat_data);
209	if (ocd->ocd_str == NULL)
210		return (ENXIO);
211
212	device_set_desc(dev, "ARM Power State Co-ordination Interface Driver");
213
214	return (BUS_PROBE_SPECIFIC);
215}
216
217static int
218psci_fdt_attach(device_t dev)
219{
220	const struct ofw_compat_data *ocd;
221	struct psci_init_def *psci_init_def;
222
223	ocd = ofw_bus_search_compatible(dev, compat_data);
224	psci_init_def = (struct psci_init_def *)ocd->ocd_data;
225
226	return (psci_attach(dev, psci_init_def->psci_init,
227	    psci_init_def->default_version));
228}
229#endif
230
231#ifdef DEV_ACPI
232static void psci_acpi_identify(driver_t *, device_t);
233static int psci_acpi_probe(device_t);
234static int psci_acpi_attach(device_t);
235
236static device_method_t psci_acpi_methods[] = {
237	/* Device interface */
238	DEVMETHOD(device_identify,	psci_acpi_identify),
239	DEVMETHOD(device_probe,		psci_acpi_probe),
240	DEVMETHOD(device_attach,	psci_acpi_attach),
241
242	DEVMETHOD_END
243};
244
245static driver_t psci_acpi_driver = {
246	"psci",
247	psci_acpi_methods,
248	sizeof(struct psci_softc),
249};
250
251static devclass_t psci_acpi_devclass;
252
253EARLY_DRIVER_MODULE(psci, acpi, psci_acpi_driver, psci_acpi_devclass, 0, 0,
254    BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);
255
256static int
257psci_acpi_bootflags(void)
258{
259	ACPI_TABLE_FADT *fadt;
260	vm_paddr_t physaddr;
261	int flags;
262
263	physaddr = acpi_find_table(ACPI_SIG_FADT);
264	if (physaddr == 0)
265		return (0);
266
267	fadt = acpi_map_table(physaddr, ACPI_SIG_FADT);
268	if (fadt == NULL) {
269		printf("psci: Unable to map the FADT\n");
270		return (0);
271	}
272
273	flags = fadt->ArmBootFlags;
274
275	acpi_unmap_table(fadt);
276	return (flags);
277}
278
279static psci_callfn_t
280psci_acpi_get_callfn(int flags)
281{
282
283	if ((flags & ACPI_FADT_PSCI_COMPLIANT) != 0) {
284		if ((flags & ACPI_FADT_PSCI_USE_HVC) != 0)
285			return (psci_hvc_despatch);
286		else
287			return (psci_smc_despatch);
288	} else {
289		printf("psci: PSCI conduit not supplied in the device tree\n");
290	}
291
292	return (NULL);
293}
294
295static void
296psci_acpi_identify(driver_t *driver, device_t parent)
297{
298	device_t dev;
299	int flags;
300
301	flags = psci_acpi_bootflags();
302	if ((flags & ACPI_FADT_PSCI_COMPLIANT) != 0) {
303		dev = BUS_ADD_CHILD(parent,
304		    BUS_PASS_CPU + BUS_PASS_ORDER_FIRST, "psci", -1);
305
306		if (dev != NULL)
307			acpi_set_private(dev, (void *)(uintptr_t)flags);
308	}
309}
310
311static int
312psci_acpi_probe(device_t dev)
313{
314	uintptr_t flags;
315
316	flags = (uintptr_t)acpi_get_private(dev);
317	if ((flags & ACPI_FADT_PSCI_COMPLIANT) == 0)
318		return (ENXIO);
319
320	device_set_desc(dev, "ARM Power State Co-ordination Interface Driver");
321	return (BUS_PROBE_SPECIFIC);
322}
323
324static int
325psci_acpi_attach(device_t dev)
326{
327
328	return (psci_attach(dev, psci_v0_2_init, PSCI_RETVAL_NOT_SUPPORTED));
329}
330#endif
331
332static int
333psci_attach(device_t dev, psci_initfn_t psci_init, int default_version)
334{
335	struct psci_softc *sc = device_get_softc(dev);
336
337	if (psci_softc != NULL)
338		return (ENXIO);
339
340	KASSERT(psci_init != NULL, ("PSCI init function cannot be NULL"));
341	if (psci_init(dev, default_version))
342		return (ENXIO);
343
344	psci_softc = sc;
345
346	return (0);
347}
348
349static int
350_psci_get_version(struct psci_softc *sc)
351{
352	uint32_t fnid;
353
354	/* PSCI version wasn't supported in v0.1. */
355	fnid = sc->psci_fnids[PSCI_FN_VERSION];
356	if (fnid)
357		return (psci_call(fnid, 0, 0, 0));
358
359	return (PSCI_RETVAL_NOT_SUPPORTED);
360}
361
362int
363psci_get_version(void)
364{
365
366	if (psci_softc == NULL)
367		return (PSCI_RETVAL_NOT_SUPPORTED);
368	return (_psci_get_version(psci_softc));
369}
370
371#ifdef FDT
372static int
373psci_fdt_callfn(psci_callfn_t *callfn)
374{
375	phandle_t node;
376
377	node = ofw_bus_find_compatible(OF_peer(0), "arm,psci-0.2");
378	if (node == 0) {
379		node = ofw_bus_find_compatible(OF_peer(0), "arm,psci-1.0");
380		if (node == 0)
381			return (PSCI_MISSING);
382	}
383
384	*callfn = psci_fdt_get_callfn(node);
385	return (0);
386}
387#endif
388
389#ifdef DEV_ACPI
390static int
391psci_acpi_callfn(psci_callfn_t *callfn)
392{
393	int flags;
394
395	flags = psci_acpi_bootflags();
396	if ((flags & ACPI_FADT_PSCI_COMPLIANT) == 0)
397		return (PSCI_MISSING);
398
399	*callfn = psci_acpi_get_callfn(flags);
400	return (0);
401}
402#endif
403
404static int
405psci_find_callfn(psci_callfn_t *callfn)
406{
407	int error;
408
409	*callfn = NULL;
410#ifdef FDT
411	if (USE_FDT) {
412		error = psci_fdt_callfn(callfn);
413		if (error != 0)
414			return (error);
415	}
416#endif
417#ifdef DEV_ACPI
418	if (*callfn == NULL && USE_ACPI) {
419		error = psci_acpi_callfn(callfn);
420		if (error != 0)
421			return (error);
422	}
423#endif
424
425	if (*callfn == NULL)
426		return (PSCI_MISSING);
427
428	return (PSCI_RETVAL_SUCCESS);
429}
430
431int32_t
432psci_features(uint32_t psci_func_id)
433{
434
435	if (psci_softc == NULL)
436		return (PSCI_RETVAL_NOT_SUPPORTED);
437
438	/* The feature flags were added to PSCI 1.0 */
439	if (PSCI_VER_MAJOR(psci_softc->psci_version) < 1)
440		return (PSCI_RETVAL_NOT_SUPPORTED);
441
442	return (psci_call(PSCI_FNID_FEATURES, psci_func_id, 0, 0));
443}
444
445int
446psci_cpu_on(unsigned long cpu, unsigned long entry, unsigned long context_id)
447{
448	uint32_t fnid;
449
450	fnid = PSCI_FNID_CPU_ON;
451	if (psci_softc != NULL)
452		fnid = psci_softc->psci_fnids[PSCI_FN_CPU_ON];
453
454	/* PSCI v0.1 and v0.2 both support cpu_on. */
455	return (psci_call(fnid, cpu, entry, context_id));
456}
457
458static void
459psci_shutdown(void *xsc, int howto)
460{
461	uint32_t fn = 0;
462
463	if (psci_softc == NULL)
464		return;
465
466	/* PSCI system_off and system_reset werent't supported in v0.1. */
467	if ((howto & RB_POWEROFF) != 0)
468		fn = psci_softc->psci_fnids[PSCI_FN_SYSTEM_OFF];
469	else if ((howto & RB_HALT) == 0)
470		fn = psci_softc->psci_fnids[PSCI_FN_SYSTEM_RESET];
471
472	if (fn)
473		psci_call(fn, 0, 0, 0);
474
475	/* System reset and off do not return. */
476}
477
478void
479psci_reset(void)
480{
481
482	psci_shutdown(NULL, 0);
483}
484
485#ifdef FDT
486/* Only support PSCI 0.1 on FDT */
487static int
488psci_v0_1_init(device_t dev, int default_version __unused)
489{
490	struct psci_softc *sc = device_get_softc(dev);
491	int psci_fn;
492	uint32_t psci_fnid;
493	phandle_t node;
494	int len;
495
496
497	/* Zero out the function ID table - Is this needed ? */
498	for (psci_fn = PSCI_FN_VERSION, psci_fnid = PSCI_FNID_VERSION;
499	    psci_fn < PSCI_FN_MAX; psci_fn++, psci_fnid++)
500		sc->psci_fnids[psci_fn] = 0;
501
502	/* PSCI v0.1 doesn't specify function IDs. Get them from DT */
503	node = ofw_bus_get_node(dev);
504
505	if ((len = OF_getproplen(node, "cpu_suspend")) > 0) {
506		OF_getencprop(node, "cpu_suspend", &psci_fnid, len);
507		sc->psci_fnids[PSCI_FN_CPU_SUSPEND] = psci_fnid;
508	}
509
510	if ((len = OF_getproplen(node, "cpu_on")) > 0) {
511		OF_getencprop(node, "cpu_on", &psci_fnid, len);
512		sc->psci_fnids[PSCI_FN_CPU_ON] = psci_fnid;
513	}
514
515	if ((len = OF_getproplen(node, "cpu_off")) > 0) {
516		OF_getencprop(node, "cpu_off", &psci_fnid, len);
517		sc->psci_fnids[PSCI_FN_CPU_OFF] = psci_fnid;
518	}
519
520	if ((len = OF_getproplen(node, "migrate")) > 0) {
521		OF_getencprop(node, "migrate", &psci_fnid, len);
522		sc->psci_fnids[PSCI_FN_MIGRATE] = psci_fnid;
523	}
524
525	sc->psci_version = (0 << 16) | 1;
526	if (bootverbose)
527		device_printf(dev, "PSCI version 0.1 available\n");
528
529	return(0);
530}
531#endif
532
533static int
534psci_v0_2_init(device_t dev, int default_version)
535{
536	struct psci_softc *sc = device_get_softc(dev);
537	int version;
538
539	/* PSCI v0.2 specifies explicit function IDs. */
540	sc->psci_fnids[PSCI_FN_VERSION]		    = PSCI_FNID_VERSION;
541	sc->psci_fnids[PSCI_FN_CPU_SUSPEND]	    = PSCI_FNID_CPU_SUSPEND;
542	sc->psci_fnids[PSCI_FN_CPU_OFF]		    = PSCI_FNID_CPU_OFF;
543	sc->psci_fnids[PSCI_FN_CPU_ON]		    = PSCI_FNID_CPU_ON;
544	sc->psci_fnids[PSCI_FN_AFFINITY_INFO]	    = PSCI_FNID_AFFINITY_INFO;
545	sc->psci_fnids[PSCI_FN_MIGRATE]		    = PSCI_FNID_MIGRATE;
546	sc->psci_fnids[PSCI_FN_MIGRATE_INFO_TYPE]   = PSCI_FNID_MIGRATE_INFO_TYPE;
547	sc->psci_fnids[PSCI_FN_MIGRATE_INFO_UP_CPU] = PSCI_FNID_MIGRATE_INFO_UP_CPU;
548	sc->psci_fnids[PSCI_FN_SYSTEM_OFF]	    = PSCI_FNID_SYSTEM_OFF;
549	sc->psci_fnids[PSCI_FN_SYSTEM_RESET]	    = PSCI_FNID_SYSTEM_RESET;
550
551	version = _psci_get_version(sc);
552
553	/*
554	 * U-Boot PSCI implementation doesn't have psci_get_version()
555	 * method implemented for many boards. In this case, use the version
556	 * readed from FDT as fallback. No fallback method for ACPI.
557	 */
558	if (version == PSCI_RETVAL_NOT_SUPPORTED) {
559		if (default_version == PSCI_RETVAL_NOT_SUPPORTED)
560			return (1);
561
562		version = default_version;
563		printf("PSCI get_version() function is not implemented, "
564		    " assuming v%d.%d\n", PSCI_VER_MAJOR(version),
565		    PSCI_VER_MINOR(version));
566	}
567
568	sc->psci_version = version;
569	if ((PSCI_VER_MAJOR(version) == 0 && PSCI_VER_MINOR(version) == 2) ||
570	    PSCI_VER_MAJOR(version) == 1) {
571		if (bootverbose)
572			device_printf(dev, "PSCI version 0.2 compatible\n");
573
574		/*
575		 * We only register this for v0.2 since v0.1 doesn't support
576		 * system_reset.
577		 */
578		EVENTHANDLER_REGISTER(shutdown_final, psci_shutdown, sc,
579		    SHUTDOWN_PRI_LAST);
580
581		return (0);
582	}
583
584	device_printf(dev, "PSCI version number mismatched with DT\n");
585	return (1);
586}
587