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#include "opt_acpi.h"
45#include "opt_platform.h"
46
47#include <sys/param.h>
48#include <sys/systm.h>
49#include <sys/bus.h>
50#include <sys/eventhandler.h>
51#include <sys/kernel.h>
52#include <sys/module.h>
53#include <sys/reboot.h>
54
55#include <machine/bus.h>
56#include <machine/machdep.h>
57
58#ifdef DEV_ACPI
59#include <contrib/dev/acpica/include/acpi.h>
60#include <dev/acpica/acpivar.h>
61#endif
62
63#ifdef FDT
64#include <dev/fdt/fdt_common.h>
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#include <dev/psci/psci.h>
71
72struct psci_softc {
73	device_t        dev;
74
75	uint32_t	psci_version;
76	uint32_t	psci_fnids[PSCI_FN_MAX];
77};
78
79#ifdef FDT
80static int psci_v0_1_init(device_t dev, int default_version);
81#endif
82static int psci_v0_2_init(device_t dev, int default_version);
83
84struct psci_softc *psci_softc = NULL;
85bool psci_present;
86
87#ifdef __arm__
88#define	USE_ACPI	0
89#define	USE_FDT		1
90#elif defined(__aarch64__)
91#define	USE_ACPI	(arm64_bus_method == ARM64_BUS_ACPI)
92#define	USE_FDT		(arm64_bus_method == ARM64_BUS_FDT)
93#else
94#error Unknown architecture
95#endif
96
97#ifdef FDT
98struct psci_init_def {
99	int		default_version;
100	psci_initfn_t	psci_init;
101};
102
103static struct psci_init_def psci_v1_0_init_def = {
104	.default_version = (1 << 16) | 0,
105	.psci_init = psci_v0_2_init
106};
107
108static struct psci_init_def psci_v0_2_init_def = {
109	.default_version = (0 << 16) | 2,
110	.psci_init = psci_v0_2_init
111};
112
113static struct psci_init_def psci_v0_1_init_def = {
114	.default_version = (0 << 16) | 1,
115	.psci_init = psci_v0_1_init
116};
117
118static struct ofw_compat_data compat_data[] = {
119	{"arm,psci-1.0",        (uintptr_t)&psci_v1_0_init_def},
120	{"arm,psci-0.2",        (uintptr_t)&psci_v0_2_init_def},
121	{"arm,psci",            (uintptr_t)&psci_v0_1_init_def},
122	{NULL,                  0}
123};
124#endif
125
126static int psci_attach(device_t, psci_initfn_t, int);
127
128static int psci_find_callfn(psci_callfn_t *);
129static int psci_def_callfn(register_t, register_t, register_t, register_t,
130	register_t, register_t, register_t, register_t,
131	struct arm_smccc_res *res);
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	psci_present = true;
147}
148/* This needs to be before cpu_mp at SI_SUB_CPU, SI_ORDER_THIRD */
149SYSINIT(psci_start, SI_SUB_CPU, SI_ORDER_FIRST, psci_init, NULL);
150
151static int
152psci_def_callfn(register_t a __unused, register_t b __unused,
153    register_t c __unused, register_t d __unused,
154    register_t e __unused, register_t f __unused,
155    register_t g __unused, register_t h __unused,
156    struct arm_smccc_res *res __unused)
157{
158
159	panic("No PSCI/SMCCC call function set");
160}
161
162#ifdef FDT
163static int psci_fdt_probe(device_t dev);
164static int psci_fdt_attach(device_t dev);
165
166static device_method_t psci_fdt_methods[] = {
167	DEVMETHOD(device_probe,     psci_fdt_probe),
168	DEVMETHOD(device_attach,    psci_fdt_attach),
169
170	DEVMETHOD_END
171};
172
173static driver_t psci_fdt_driver = {
174	"psci",
175	psci_fdt_methods,
176	sizeof(struct psci_softc),
177};
178
179EARLY_DRIVER_MODULE(psci, simplebus, psci_fdt_driver, 0, 0,
180    BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);
181EARLY_DRIVER_MODULE(psci, ofwbus, psci_fdt_driver, 0, 0,
182    BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);
183
184static psci_callfn_t
185psci_fdt_get_callfn(phandle_t node)
186{
187	char method[16];
188
189	if ((OF_getprop(node, "method", method, sizeof(method))) > 0) {
190		if (strcmp(method, "hvc") == 0)
191			return (arm_smccc_hvc);
192		else if (strcmp(method, "smc") == 0)
193			return (arm_smccc_smc);
194		else
195			printf("psci: PSCI conduit \"%s\" invalid\n", method);
196	} else
197		printf("psci: PSCI conduit not supplied in the device tree\n");
198
199	return (NULL);
200}
201
202static int
203psci_fdt_probe(device_t dev)
204{
205	const struct ofw_compat_data *ocd;
206
207	if (!ofw_bus_status_okay(dev))
208		return (ENXIO);
209
210	ocd = ofw_bus_search_compatible(dev, compat_data);
211	if (ocd->ocd_str == NULL)
212		return (ENXIO);
213
214	device_set_desc(dev, "ARM Power State Co-ordination Interface Driver");
215
216	return (BUS_PROBE_SPECIFIC);
217}
218
219static int
220psci_fdt_attach(device_t dev)
221{
222	const struct ofw_compat_data *ocd;
223	struct psci_init_def *psci_init_def;
224
225	ocd = ofw_bus_search_compatible(dev, compat_data);
226	psci_init_def = (struct psci_init_def *)ocd->ocd_data;
227
228	return (psci_attach(dev, psci_init_def->psci_init,
229	    psci_init_def->default_version));
230}
231#endif
232
233#ifdef DEV_ACPI
234static void psci_acpi_identify(driver_t *, device_t);
235static int psci_acpi_probe(device_t);
236static int psci_acpi_attach(device_t);
237
238static device_method_t psci_acpi_methods[] = {
239	/* Device interface */
240	DEVMETHOD(device_identify,	psci_acpi_identify),
241	DEVMETHOD(device_probe,		psci_acpi_probe),
242	DEVMETHOD(device_attach,	psci_acpi_attach),
243
244	DEVMETHOD_END
245};
246
247static driver_t psci_acpi_driver = {
248	"psci",
249	psci_acpi_methods,
250	sizeof(struct psci_softc),
251};
252
253EARLY_DRIVER_MODULE(psci, acpi, psci_acpi_driver, 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 (arm_smccc_hvc);
286		else
287			return (arm_smccc_smc);
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#ifdef __aarch64__
345	smccc_init();
346#endif
347
348	psci_softc = sc;
349
350	return (0);
351}
352
353static int
354_psci_get_version(struct psci_softc *sc)
355{
356	uint32_t fnid;
357
358	/* PSCI version wasn't supported in v0.1. */
359	fnid = sc->psci_fnids[PSCI_FN_VERSION];
360	if (fnid)
361		return (psci_call(fnid, 0, 0, 0));
362
363	return (PSCI_RETVAL_NOT_SUPPORTED);
364}
365
366int
367psci_get_version(void)
368{
369
370	if (psci_softc == NULL)
371		return (PSCI_RETVAL_NOT_SUPPORTED);
372	return (_psci_get_version(psci_softc));
373}
374
375#ifdef FDT
376static int
377psci_fdt_callfn(psci_callfn_t *callfn)
378{
379	phandle_t node;
380
381	/* XXX: This is suboptimal, we should walk the tree & check each
382	 * node against compat_data, but we only have a few entries so
383	 * it's ok for now.
384	 */
385	for (int i = 0; compat_data[i].ocd_str != NULL; i++) {
386		node = ofw_bus_find_compatible(OF_peer(0),
387		    compat_data[i].ocd_str);
388		if (node != 0)
389			break;
390	}
391	if (node == 0)
392		return (PSCI_MISSING);
393
394	if (!ofw_bus_node_status_okay(node))
395		return (PSCI_MISSING);
396
397	*callfn = psci_fdt_get_callfn(node);
398	return (0);
399}
400#endif
401
402#ifdef DEV_ACPI
403static int
404psci_acpi_callfn(psci_callfn_t *callfn)
405{
406	int flags;
407
408	flags = psci_acpi_bootflags();
409	if ((flags & ACPI_FADT_PSCI_COMPLIANT) == 0)
410		return (PSCI_MISSING);
411
412	*callfn = psci_acpi_get_callfn(flags);
413	return (0);
414}
415#endif
416
417static int
418psci_find_callfn(psci_callfn_t *callfn)
419{
420	int error;
421
422	*callfn = NULL;
423#ifdef FDT
424	if (USE_FDT) {
425		error = psci_fdt_callfn(callfn);
426		if (error != 0)
427			return (error);
428	}
429#endif
430#ifdef DEV_ACPI
431	if (*callfn == NULL && USE_ACPI) {
432		error = psci_acpi_callfn(callfn);
433		if (error != 0)
434			return (error);
435	}
436#endif
437
438	if (*callfn == NULL)
439		return (PSCI_MISSING);
440
441	return (PSCI_RETVAL_SUCCESS);
442}
443
444int32_t
445psci_features(uint32_t psci_func_id)
446{
447
448	if (psci_softc == NULL)
449		return (PSCI_RETVAL_NOT_SUPPORTED);
450
451	/* The feature flags were added to PSCI 1.0 */
452	if (PSCI_VER_MAJOR(psci_softc->psci_version) < 1)
453		return (PSCI_RETVAL_NOT_SUPPORTED);
454
455	return (psci_call(PSCI_FNID_FEATURES, psci_func_id, 0, 0));
456}
457
458int
459psci_cpu_on(unsigned long cpu, unsigned long entry, unsigned long context_id)
460{
461	uint32_t fnid;
462
463	fnid = PSCI_FNID_CPU_ON;
464	if (psci_softc != NULL)
465		fnid = psci_softc->psci_fnids[PSCI_FN_CPU_ON];
466
467	/* PSCI v0.1 and v0.2 both support cpu_on. */
468	return (psci_call(fnid, cpu, entry, context_id));
469}
470
471static void
472psci_shutdown(void *xsc, int howto)
473{
474	uint32_t fn = 0;
475
476	if (psci_softc == NULL)
477		return;
478
479	if ((howto & RB_POWEROFF) != 0)
480		fn = psci_softc->psci_fnids[PSCI_FN_SYSTEM_OFF];
481	if (fn)
482		psci_call(fn, 0, 0, 0);
483
484	/* System reset and off do not return. */
485}
486
487static void
488psci_reboot(void *xsc, int howto)
489{
490	uint32_t fn = 0;
491
492	if (psci_softc == NULL)
493		return;
494
495	if ((howto & RB_HALT) == 0)
496		fn = psci_softc->psci_fnids[PSCI_FN_SYSTEM_RESET];
497	if (fn)
498		psci_call(fn, 0, 0, 0);
499
500	/* System reset and off do not return. */
501}
502
503void
504psci_reset(void)
505{
506
507	psci_reboot(NULL, 0);
508}
509
510#ifdef FDT
511/* Only support PSCI 0.1 on FDT */
512static int
513psci_v0_1_init(device_t dev, int default_version __unused)
514{
515	struct psci_softc *sc = device_get_softc(dev);
516	int psci_fn;
517	uint32_t psci_fnid;
518	phandle_t node;
519	int len;
520
521	/* Zero out the function ID table - Is this needed ? */
522	for (psci_fn = PSCI_FN_VERSION, psci_fnid = PSCI_FNID_VERSION;
523	    psci_fn < PSCI_FN_MAX; psci_fn++, psci_fnid++)
524		sc->psci_fnids[psci_fn] = 0;
525
526	/* PSCI v0.1 doesn't specify function IDs. Get them from DT */
527	node = ofw_bus_get_node(dev);
528
529	if ((len = OF_getproplen(node, "cpu_suspend")) > 0) {
530		OF_getencprop(node, "cpu_suspend", &psci_fnid, len);
531		sc->psci_fnids[PSCI_FN_CPU_SUSPEND] = psci_fnid;
532	}
533
534	if ((len = OF_getproplen(node, "cpu_on")) > 0) {
535		OF_getencprop(node, "cpu_on", &psci_fnid, len);
536		sc->psci_fnids[PSCI_FN_CPU_ON] = psci_fnid;
537	}
538
539	if ((len = OF_getproplen(node, "cpu_off")) > 0) {
540		OF_getencprop(node, "cpu_off", &psci_fnid, len);
541		sc->psci_fnids[PSCI_FN_CPU_OFF] = psci_fnid;
542	}
543
544	if ((len = OF_getproplen(node, "migrate")) > 0) {
545		OF_getencprop(node, "migrate", &psci_fnid, len);
546		sc->psci_fnids[PSCI_FN_MIGRATE] = psci_fnid;
547	}
548
549	sc->psci_version = (0 << 16) | 1;
550	if (bootverbose)
551		device_printf(dev, "PSCI version 0.1 available\n");
552
553	return(0);
554}
555#endif
556
557static int
558psci_v0_2_init(device_t dev, int default_version)
559{
560	struct psci_softc *sc = device_get_softc(dev);
561	int version;
562
563	/* PSCI v0.2 specifies explicit function IDs. */
564	sc->psci_fnids[PSCI_FN_VERSION]		    = PSCI_FNID_VERSION;
565	sc->psci_fnids[PSCI_FN_CPU_SUSPEND]	    = PSCI_FNID_CPU_SUSPEND;
566	sc->psci_fnids[PSCI_FN_CPU_OFF]		    = PSCI_FNID_CPU_OFF;
567	sc->psci_fnids[PSCI_FN_CPU_ON]		    = PSCI_FNID_CPU_ON;
568	sc->psci_fnids[PSCI_FN_AFFINITY_INFO]	    = PSCI_FNID_AFFINITY_INFO;
569	sc->psci_fnids[PSCI_FN_MIGRATE]		    = PSCI_FNID_MIGRATE;
570	sc->psci_fnids[PSCI_FN_MIGRATE_INFO_TYPE]   = PSCI_FNID_MIGRATE_INFO_TYPE;
571	sc->psci_fnids[PSCI_FN_MIGRATE_INFO_UP_CPU] = PSCI_FNID_MIGRATE_INFO_UP_CPU;
572	sc->psci_fnids[PSCI_FN_SYSTEM_OFF]	    = PSCI_FNID_SYSTEM_OFF;
573	sc->psci_fnids[PSCI_FN_SYSTEM_RESET]	    = PSCI_FNID_SYSTEM_RESET;
574
575	version = _psci_get_version(sc);
576
577	/*
578	 * U-Boot PSCI implementation doesn't have psci_get_version()
579	 * method implemented for many boards. In this case, use the version
580	 * readed from FDT as fallback. No fallback method for ACPI.
581	 */
582	if (version == PSCI_RETVAL_NOT_SUPPORTED) {
583		if (default_version == PSCI_RETVAL_NOT_SUPPORTED)
584			return (1);
585
586		version = default_version;
587		printf("PSCI get_version() function is not implemented, "
588		    " assuming v%d.%d\n", PSCI_VER_MAJOR(version),
589		    PSCI_VER_MINOR(version));
590	}
591
592	sc->psci_version = version;
593	if ((PSCI_VER_MAJOR(version) == 0 && PSCI_VER_MINOR(version) == 2) ||
594	    PSCI_VER_MAJOR(version) == 1) {
595		if (bootverbose)
596			device_printf(dev, "PSCI version 0.2 compatible\n");
597
598		/*
599		 * We only register this for v0.2 since v0.1 doesn't support
600		 * system_reset.
601		 */
602		EVENTHANDLER_REGISTER(shutdown_final, psci_shutdown, sc,
603		    SHUTDOWN_PRI_LAST);
604
605		/* Handle reboot after shutdown_panic. */
606		EVENTHANDLER_REGISTER(shutdown_final, psci_reboot, sc,
607		    SHUTDOWN_PRI_LAST + 150);
608
609		return (0);
610	}
611
612	device_printf(dev, "PSCI version number mismatched with DT\n");
613	return (1);
614}
615