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acpi_cpu_pstate.c revision 1.45.2.3
      1 /* $NetBSD: acpi_cpu_pstate.c,v 1.45.2.3 2011/03/06 00:27:00 rmind Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2010, 2011 Jukka Ruohonen <jruohonen (at) iki.fi>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  *
     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  *
     17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     27  * SUCH DAMAGE.
     28  */
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: acpi_cpu_pstate.c,v 1.45.2.3 2011/03/06 00:27:00 rmind Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/kmem.h>
     34 #include <sys/once.h>
     35 #include <sys/xcall.h>
     36 
     37 #include <dev/acpi/acpireg.h>
     38 #include <dev/acpi/acpivar.h>
     39 #include <dev/acpi/acpi_cpu.h>
     40 
     41 #define _COMPONENT	 ACPI_BUS_COMPONENT
     42 ACPI_MODULE_NAME	 ("acpi_cpu_pstate")
     43 
     44 static ACPI_STATUS	 acpicpu_pstate_pss(struct acpicpu_softc *);
     45 static ACPI_STATUS	 acpicpu_pstate_pss_add(struct acpicpu_pstate *,
     46 						ACPI_OBJECT *);
     47 static ACPI_STATUS	 acpicpu_pstate_xpss(struct acpicpu_softc *);
     48 static ACPI_STATUS	 acpicpu_pstate_xpss_add(struct acpicpu_pstate *,
     49 						 ACPI_OBJECT *);
     50 static ACPI_STATUS	 acpicpu_pstate_pct(struct acpicpu_softc *);
     51 static ACPI_STATUS	 acpicpu_pstate_dep(struct acpicpu_softc *);
     52 static int		 acpicpu_pstate_max(struct acpicpu_softc *);
     53 static int		 acpicpu_pstate_min(struct acpicpu_softc *);
     54 static void		 acpicpu_pstate_change(struct acpicpu_softc *);
     55 static void		 acpicpu_pstate_reset(struct acpicpu_softc *);
     56 static void		 acpicpu_pstate_bios(void);
     57 static void		 acpicpu_pstate_set_xcall(void *, void *);
     58 
     59 static uint32_t acpicpu_pstate_saved = 0;
     60 extern struct acpicpu_softc **acpicpu_sc;
     61 
     62 void
     63 acpicpu_pstate_attach(device_t self)
     64 {
     65 	struct acpicpu_softc *sc = device_private(self);
     66 	const char *str;
     67 	ACPI_HANDLE tmp;
     68 	ACPI_STATUS rv;
     69 
     70 	rv = acpicpu_pstate_pss(sc);
     71 
     72 	if (ACPI_FAILURE(rv)) {
     73 		str = "_PSS";
     74 		goto fail;
     75 	}
     76 
     77 	/*
     78 	 * Append additional information from the extended _PSS,
     79 	 * if available. Note that XPSS can not be used on Intel
     80 	 * systems that use either _PDC or _OSC. From the XPSS
     81 	 * method specification:
     82 	 *
     83 	 *   "The platform must not require the use of the
     84 	 *    optional _PDC or _OSC methods to coordinate
     85 	 *    between the operating system and firmware for
     86 	 *    the purposes of enabling specific processor
     87 	 *    power management features or implementations."
     88 	 */
     89 	if (sc->sc_cap == 0) {
     90 
     91 		rv = acpicpu_pstate_xpss(sc);
     92 
     93 		if (ACPI_SUCCESS(rv))
     94 			sc->sc_flags |= ACPICPU_FLAG_P_XPSS;
     95 	}
     96 
     97 	rv = acpicpu_pstate_pct(sc);
     98 
     99 	if (ACPI_FAILURE(rv)) {
    100 		str = "_PCT";
    101 		goto fail;
    102 	}
    103 
    104 	/*
    105 	 * The ACPI 3.0 and 4.0 specifications mandate three
    106 	 * objects for P-states: _PSS, _PCT, and _PPC. A less
    107 	 * strict wording is however used in the earlier 2.0
    108 	 * standard, and some systems conforming to ACPI 2.0
    109 	 * do not have _PPC, the method for dynamic maximum.
    110 	 */
    111 	rv = AcpiGetHandle(sc->sc_node->ad_handle, "_PPC", &tmp);
    112 
    113 	if (ACPI_FAILURE(rv))
    114 		aprint_debug_dev(self, "_PPC missing\n");
    115 
    116 	/*
    117 	 * Carry out MD initialization.
    118 	 */
    119 	rv = acpicpu_md_pstate_init(sc);
    120 
    121 	if (rv != 0) {
    122 		rv = AE_SUPPORT;
    123 		goto fail;
    124 	}
    125 
    126 	/*
    127 	 * Query the optional _PSD.
    128 	 */
    129 	rv = acpicpu_pstate_dep(sc);
    130 
    131 	if (ACPI_SUCCESS(rv))
    132 		sc->sc_flags |= ACPICPU_FLAG_P_DEP;
    133 
    134 	sc->sc_flags |= ACPICPU_FLAG_P;
    135 
    136 	acpicpu_pstate_bios();
    137 	acpicpu_pstate_reset(sc);
    138 
    139 	return;
    140 
    141 fail:
    142 	switch (rv) {
    143 
    144 	case AE_NOT_FOUND:
    145 		return;
    146 
    147 	case AE_SUPPORT:
    148 		aprint_verbose_dev(self, "P-states not supported\n");
    149 		return;
    150 
    151 	default:
    152 		aprint_error_dev(self, "failed to evaluate "
    153 		    "%s: %s\n", str, AcpiFormatException(rv));
    154 	}
    155 }
    156 
    157 int
    158 acpicpu_pstate_detach(device_t self)
    159 {
    160 	struct acpicpu_softc *sc = device_private(self);
    161 	static ONCE_DECL(once_detach);
    162 	size_t size;
    163 	int rv;
    164 
    165 	if ((sc->sc_flags & ACPICPU_FLAG_P) == 0)
    166 		return 0;
    167 
    168 	rv = RUN_ONCE(&once_detach, acpicpu_md_pstate_stop);
    169 
    170 	if (rv != 0)
    171 		return rv;
    172 
    173 	size = sc->sc_pstate_count * sizeof(*sc->sc_pstate);
    174 
    175 	if (sc->sc_pstate != NULL)
    176 		kmem_free(sc->sc_pstate, size);
    177 
    178 	sc->sc_flags &= ~ACPICPU_FLAG_P;
    179 
    180 	return 0;
    181 }
    182 
    183 void
    184 acpicpu_pstate_start(device_t self)
    185 {
    186 	struct acpicpu_softc *sc = device_private(self);
    187 	struct acpicpu_pstate *ps;
    188 	uint32_t i;
    189 	int rv;
    190 
    191 	rv = acpicpu_md_pstate_start(sc);
    192 
    193 	if (rv != 0)
    194 		goto fail;
    195 
    196 	/*
    197 	 * Initialize the states to P0.
    198 	 */
    199 	for (i = 0, rv = ENXIO; i < sc->sc_pstate_count; i++) {
    200 
    201 		ps = &sc->sc_pstate[i];
    202 
    203 		if (ps->ps_freq != 0) {
    204 			acpicpu_pstate_set(sc->sc_ci, ps->ps_freq);
    205 			return;
    206 		}
    207 	}
    208 
    209 fail:
    210 	sc->sc_flags &= ~ACPICPU_FLAG_P;
    211 	aprint_error_dev(self, "failed to start P-states (err %d)\n", rv);
    212 }
    213 
    214 bool
    215 acpicpu_pstate_suspend(device_t self)
    216 {
    217 	struct acpicpu_softc *sc = device_private(self);
    218 	struct acpicpu_pstate *ps = NULL;
    219 	int32_t i;
    220 
    221 	mutex_enter(&sc->sc_mtx);
    222 	acpicpu_pstate_reset(sc);
    223 	mutex_exit(&sc->sc_mtx);
    224 
    225 	if (acpicpu_pstate_saved != 0)
    226 		return true;
    227 
    228 	/*
    229 	 * Following design notes for Windows, we set the highest
    230 	 * P-state when entering any of the system sleep states.
    231 	 * When resuming, the saved P-state will be restored.
    232 	 *
    233 	 *	Microsoft Corporation: Windows Native Processor
    234 	 *	Performance Control. Version 1.1a, November, 2002.
    235 	 */
    236 	for (i = sc->sc_pstate_count - 1; i >= 0; i--) {
    237 
    238 		if (sc->sc_pstate[i].ps_freq != 0) {
    239 			ps = &sc->sc_pstate[i];
    240 			break;
    241 		}
    242 	}
    243 
    244 	if (__predict_false(ps == NULL))
    245 		return true;
    246 
    247 	mutex_enter(&sc->sc_mtx);
    248 	acpicpu_pstate_saved = sc->sc_pstate_current;
    249 	mutex_exit(&sc->sc_mtx);
    250 
    251 	if (acpicpu_pstate_saved == ps->ps_freq)
    252 		return true;
    253 
    254 	acpicpu_pstate_set(sc->sc_ci, ps->ps_freq);
    255 
    256 	return true;
    257 }
    258 
    259 bool
    260 acpicpu_pstate_resume(device_t self)
    261 {
    262 	struct acpicpu_softc *sc = device_private(self);
    263 
    264 	if (acpicpu_pstate_saved != 0) {
    265 		acpicpu_pstate_set(sc->sc_ci, acpicpu_pstate_saved);
    266 		acpicpu_pstate_saved = 0;
    267 	}
    268 
    269 	return true;
    270 }
    271 
    272 void
    273 acpicpu_pstate_callback(void *aux)
    274 {
    275 	struct acpicpu_softc *sc;
    276 	device_t self = aux;
    277 	uint32_t old, new;
    278 
    279 	sc = device_private(self);
    280 
    281 	mutex_enter(&sc->sc_mtx);
    282 
    283 	old = sc->sc_pstate_max;
    284 	acpicpu_pstate_change(sc);
    285 	new = sc->sc_pstate_max;
    286 
    287 	if (old == new) {
    288 		mutex_exit(&sc->sc_mtx);
    289 		return;
    290 	}
    291 
    292 	mutex_exit(&sc->sc_mtx);
    293 
    294 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "maximum frequency "
    295 		"changed from P%u (%u MHz) to P%u (%u MHz)\n",
    296 		old, sc->sc_pstate[old].ps_freq, new,
    297 		sc->sc_pstate[sc->sc_pstate_max].ps_freq));
    298 
    299 	acpicpu_pstate_set(sc->sc_ci, sc->sc_pstate[new].ps_freq);
    300 }
    301 
    302 ACPI_STATUS
    303 acpicpu_pstate_pss(struct acpicpu_softc *sc)
    304 {
    305 	struct acpicpu_pstate *ps;
    306 	ACPI_OBJECT *obj;
    307 	ACPI_BUFFER buf;
    308 	ACPI_STATUS rv;
    309 	uint32_t count;
    310 	uint32_t i, j;
    311 
    312 	rv = acpi_eval_struct(sc->sc_node->ad_handle, "_PSS", &buf);
    313 
    314 	if (ACPI_FAILURE(rv))
    315 		return rv;
    316 
    317 	obj = buf.Pointer;
    318 
    319 	if (obj->Type != ACPI_TYPE_PACKAGE) {
    320 		rv = AE_TYPE;
    321 		goto out;
    322 	}
    323 
    324 	sc->sc_pstate_count = obj->Package.Count;
    325 
    326 	if (sc->sc_pstate_count == 0) {
    327 		rv = AE_NOT_EXIST;
    328 		goto out;
    329 	}
    330 
    331 	if (sc->sc_pstate_count > ACPICPU_P_STATE_MAX) {
    332 		rv = AE_LIMIT;
    333 		goto out;
    334 	}
    335 
    336 	sc->sc_pstate = kmem_zalloc(sc->sc_pstate_count *
    337 	    sizeof(struct acpicpu_pstate), KM_SLEEP);
    338 
    339 	if (sc->sc_pstate == NULL) {
    340 		rv = AE_NO_MEMORY;
    341 		goto out;
    342 	}
    343 
    344 	for (count = i = 0; i < sc->sc_pstate_count; i++) {
    345 
    346 		ps = &sc->sc_pstate[i];
    347 		rv = acpicpu_pstate_pss_add(ps, &obj->Package.Elements[i]);
    348 
    349 		if (ACPI_FAILURE(rv)) {
    350 			aprint_error_dev(sc->sc_dev, "failed to add "
    351 			    "P-state: %s\n", AcpiFormatException(rv));
    352 			ps->ps_freq = 0;
    353 			continue;
    354 		}
    355 
    356 		for (j = 0; j < i; j++) {
    357 
    358 			if (ps->ps_freq >= sc->sc_pstate[j].ps_freq) {
    359 				ps->ps_freq = 0;
    360 				break;
    361 			}
    362 		}
    363 
    364 		if (ps->ps_freq != 0)
    365 			count++;
    366 	}
    367 
    368 	rv = (count != 0) ? AE_OK : AE_NOT_EXIST;
    369 
    370 out:
    371 	if (buf.Pointer != NULL)
    372 		ACPI_FREE(buf.Pointer);
    373 
    374 	return rv;
    375 }
    376 
    377 static ACPI_STATUS
    378 acpicpu_pstate_pss_add(struct acpicpu_pstate *ps, ACPI_OBJECT *obj)
    379 {
    380 	ACPI_OBJECT *elm;
    381 	int i;
    382 
    383 	if (obj->Type != ACPI_TYPE_PACKAGE)
    384 		return AE_TYPE;
    385 
    386 	if (obj->Package.Count != 6)
    387 		return AE_BAD_DATA;
    388 
    389 	elm = obj->Package.Elements;
    390 
    391 	for (i = 0; i < 6; i++) {
    392 
    393 		if (elm[i].Type != ACPI_TYPE_INTEGER)
    394 			return AE_TYPE;
    395 
    396 		if (elm[i].Integer.Value > UINT32_MAX)
    397 			return AE_AML_NUMERIC_OVERFLOW;
    398 	}
    399 
    400 	ps->ps_freq       = elm[0].Integer.Value;
    401 	ps->ps_power      = elm[1].Integer.Value;
    402 	ps->ps_latency    = elm[2].Integer.Value;
    403 	ps->ps_latency_bm = elm[3].Integer.Value;
    404 	ps->ps_control    = elm[4].Integer.Value;
    405 	ps->ps_status     = elm[5].Integer.Value;
    406 
    407 	if (ps->ps_freq == 0 || ps->ps_freq > 9999)
    408 		return AE_BAD_DECIMAL_CONSTANT;
    409 
    410 	if (ps->ps_latency == 0 || ps->ps_latency > 1000)
    411 		ps->ps_latency = 1;
    412 
    413 	return AE_OK;
    414 }
    415 
    416 static ACPI_STATUS
    417 acpicpu_pstate_xpss(struct acpicpu_softc *sc)
    418 {
    419 	struct acpicpu_pstate *ps;
    420 	ACPI_OBJECT *obj;
    421 	ACPI_BUFFER buf;
    422 	ACPI_STATUS rv;
    423 	uint32_t i = 0;
    424 
    425 	rv = acpi_eval_struct(sc->sc_node->ad_handle, "XPSS", &buf);
    426 
    427 	if (ACPI_FAILURE(rv))
    428 		goto out;
    429 
    430 	obj = buf.Pointer;
    431 
    432 	if (obj->Type != ACPI_TYPE_PACKAGE) {
    433 		rv = AE_TYPE;
    434 		goto out;
    435 	}
    436 
    437 	if (obj->Package.Count != sc->sc_pstate_count) {
    438 		rv = AE_LIMIT;
    439 		goto out;
    440 	}
    441 
    442 	while (i < sc->sc_pstate_count) {
    443 
    444 		ps = &sc->sc_pstate[i];
    445 		acpicpu_pstate_xpss_add(ps, &obj->Package.Elements[i]);
    446 
    447 		i++;
    448 	}
    449 
    450 out:
    451 	if (ACPI_FAILURE(rv) && rv != AE_NOT_FOUND)
    452 		aprint_error_dev(sc->sc_dev, "failed to evaluate "
    453 		    "XPSS: %s\n", AcpiFormatException(rv));
    454 
    455 	if (buf.Pointer != NULL)
    456 		ACPI_FREE(buf.Pointer);
    457 
    458 	return rv;
    459 }
    460 
    461 static ACPI_STATUS
    462 acpicpu_pstate_xpss_add(struct acpicpu_pstate *ps, ACPI_OBJECT *obj)
    463 {
    464 	ACPI_OBJECT *elm;
    465 	int i;
    466 
    467 	if (obj->Type != ACPI_TYPE_PACKAGE)
    468 		return AE_TYPE;
    469 
    470 	if (obj->Package.Count != 8)
    471 		return AE_BAD_DATA;
    472 
    473 	elm = obj->Package.Elements;
    474 
    475 	for (i = 0; i < 4; i++) {
    476 
    477 		if (elm[i].Type != ACPI_TYPE_INTEGER)
    478 			return AE_TYPE;
    479 
    480 		if (elm[i].Integer.Value > UINT32_MAX)
    481 			return AE_AML_NUMERIC_OVERFLOW;
    482 	}
    483 
    484 	for (; i < 8; i++) {
    485 
    486 		if (elm[i].Type != ACPI_TYPE_BUFFER)
    487 			return AE_TYPE;
    488 
    489 		if (elm[i].Buffer.Length != 8)
    490 			return AE_LIMIT;
    491 	}
    492 
    493 	/*
    494 	 * Only overwrite the elements that were
    495 	 * not available from the conventional _PSS.
    496 	 */
    497 	if (ps->ps_freq == 0)
    498 		ps->ps_freq = elm[0].Integer.Value;
    499 
    500 	if (ps->ps_power == 0)
    501 		ps->ps_power = elm[1].Integer.Value;
    502 
    503 	if (ps->ps_latency == 0)
    504 		ps->ps_latency = elm[2].Integer.Value;
    505 
    506 	if (ps->ps_latency_bm == 0)
    507 		ps->ps_latency_bm = elm[3].Integer.Value;
    508 
    509 	if (ps->ps_control == 0)
    510 		ps->ps_control = ACPI_GET64(elm[4].Buffer.Pointer);
    511 
    512 	if (ps->ps_status == 0)
    513 		ps->ps_status = ACPI_GET64(elm[5].Buffer.Pointer);
    514 
    515 	if (ps->ps_control_mask == 0)
    516 		ps->ps_control_mask = ACPI_GET64(elm[6].Buffer.Pointer);
    517 
    518 	if (ps->ps_status_mask == 0)
    519 		ps->ps_status_mask = ACPI_GET64(elm[7].Buffer.Pointer);
    520 
    521 	ps->ps_flags |= ACPICPU_FLAG_P_XPSS;
    522 
    523 	if (ps->ps_freq == 0 || ps->ps_freq > 9999)
    524 		return AE_BAD_DECIMAL_CONSTANT;
    525 
    526 	if (ps->ps_latency == 0 || ps->ps_latency > 1000)
    527 		ps->ps_latency = 1;
    528 
    529 	return AE_OK;
    530 }
    531 
    532 ACPI_STATUS
    533 acpicpu_pstate_pct(struct acpicpu_softc *sc)
    534 {
    535 	static const size_t size = sizeof(struct acpicpu_reg);
    536 	struct acpicpu_reg *reg[2];
    537 	struct acpicpu_pstate *ps;
    538 	ACPI_OBJECT *elm, *obj;
    539 	ACPI_BUFFER buf;
    540 	ACPI_STATUS rv;
    541 	uint8_t width;
    542 	uint32_t i;
    543 
    544 	rv = acpi_eval_struct(sc->sc_node->ad_handle, "_PCT", &buf);
    545 
    546 	if (ACPI_FAILURE(rv))
    547 		return rv;
    548 
    549 	obj = buf.Pointer;
    550 
    551 	if (obj->Type != ACPI_TYPE_PACKAGE) {
    552 		rv = AE_TYPE;
    553 		goto out;
    554 	}
    555 
    556 	if (obj->Package.Count != 2) {
    557 		rv = AE_LIMIT;
    558 		goto out;
    559 	}
    560 
    561 	for (i = 0; i < 2; i++) {
    562 
    563 		elm = &obj->Package.Elements[i];
    564 
    565 		if (elm->Type != ACPI_TYPE_BUFFER) {
    566 			rv = AE_TYPE;
    567 			goto out;
    568 		}
    569 
    570 		if (size > elm->Buffer.Length) {
    571 			rv = AE_AML_BAD_RESOURCE_LENGTH;
    572 			goto out;
    573 		}
    574 
    575 		reg[i] = (struct acpicpu_reg *)elm->Buffer.Pointer;
    576 
    577 		switch (reg[i]->reg_spaceid) {
    578 
    579 		case ACPI_ADR_SPACE_SYSTEM_IO:
    580 
    581 			if (reg[i]->reg_addr == 0) {
    582 				rv = AE_AML_ILLEGAL_ADDRESS;
    583 				goto out;
    584 			}
    585 
    586 			width = reg[i]->reg_bitwidth;
    587 
    588 			if (width + reg[i]->reg_bitoffset > 32) {
    589 				rv = AE_AML_BAD_RESOURCE_VALUE;
    590 				goto out;
    591 			}
    592 
    593 			if (width != 8 && width != 16 && width != 32) {
    594 				rv = AE_AML_BAD_RESOURCE_VALUE;
    595 				goto out;
    596 			}
    597 
    598 			break;
    599 
    600 		case ACPI_ADR_SPACE_FIXED_HARDWARE:
    601 
    602 			if ((sc->sc_flags & ACPICPU_FLAG_P_XPSS) != 0) {
    603 
    604 				if (reg[i]->reg_bitwidth != 64) {
    605 					rv = AE_AML_BAD_RESOURCE_VALUE;
    606 					goto out;
    607 				}
    608 
    609 				if (reg[i]->reg_bitoffset != 0) {
    610 					rv = AE_AML_BAD_RESOURCE_VALUE;
    611 					goto out;
    612 				}
    613 
    614 				break;
    615 			}
    616 
    617 			if ((sc->sc_flags & ACPICPU_FLAG_P_FFH) == 0) {
    618 				rv = AE_SUPPORT;
    619 				goto out;
    620 			}
    621 
    622 			break;
    623 
    624 		default:
    625 			rv = AE_AML_INVALID_SPACE_ID;
    626 			goto out;
    627 		}
    628 	}
    629 
    630 	if (reg[0]->reg_spaceid != reg[1]->reg_spaceid) {
    631 		rv = AE_AML_INVALID_SPACE_ID;
    632 		goto out;
    633 	}
    634 
    635 	(void)memcpy(&sc->sc_pstate_control, reg[0], size);
    636 	(void)memcpy(&sc->sc_pstate_status,  reg[1], size);
    637 
    638 	if ((sc->sc_flags & ACPICPU_FLAG_P_XPSS) == 0)
    639 		goto out;
    640 
    641 	/*
    642 	 * At the very least, mandate that
    643 	 * XPSS supplies the control address.
    644 	 */
    645 	if (sc->sc_pstate_control.reg_addr == 0) {
    646 		rv = AE_AML_BAD_RESOURCE_LENGTH;
    647 		goto out;
    648 	}
    649 
    650 	/*
    651 	 * If XPSS is present, copy the MSR addresses
    652 	 * to the P-state structures for convenience.
    653 	 */
    654 	for (i = 0; i < sc->sc_pstate_count; i++) {
    655 
    656 		ps = &sc->sc_pstate[i];
    657 
    658 		if (ps->ps_freq == 0)
    659 			continue;
    660 
    661 		ps->ps_status_addr  = sc->sc_pstate_status.reg_addr;
    662 		ps->ps_control_addr = sc->sc_pstate_control.reg_addr;
    663 	}
    664 
    665 out:
    666 	if (buf.Pointer != NULL)
    667 		ACPI_FREE(buf.Pointer);
    668 
    669 	return rv;
    670 }
    671 
    672 static ACPI_STATUS
    673 acpicpu_pstate_dep(struct acpicpu_softc *sc)
    674 {
    675 	ACPI_OBJECT *elm, *obj;
    676 	ACPI_BUFFER buf;
    677 	ACPI_STATUS rv;
    678 	uint32_t val;
    679 	uint8_t i, n;
    680 
    681 	rv = acpi_eval_struct(sc->sc_node->ad_handle, "_PSD", &buf);
    682 
    683 	if (ACPI_FAILURE(rv))
    684 		goto out;
    685 
    686 	obj = buf.Pointer;
    687 
    688 	if (obj->Type != ACPI_TYPE_PACKAGE) {
    689 		rv = AE_TYPE;
    690 		goto out;
    691 	}
    692 
    693 	if (obj->Package.Count != 1) {
    694 		rv = AE_LIMIT;
    695 		goto out;
    696 	}
    697 
    698 	elm = &obj->Package.Elements[0];
    699 
    700 	if (obj->Type != ACPI_TYPE_PACKAGE) {
    701 		rv = AE_TYPE;
    702 		goto out;
    703 	}
    704 
    705 	n = elm->Package.Count;
    706 
    707 	if (n != 5) {
    708 		rv = AE_LIMIT;
    709 		goto out;
    710 	}
    711 
    712 	elm = elm->Package.Elements;
    713 
    714 	for (i = 0; i < n; i++) {
    715 
    716 		if (elm[i].Type != ACPI_TYPE_INTEGER) {
    717 			rv = AE_TYPE;
    718 			goto out;
    719 		}
    720 
    721 		if (elm[i].Integer.Value > UINT32_MAX) {
    722 			rv = AE_AML_NUMERIC_OVERFLOW;
    723 			goto out;
    724 		}
    725 	}
    726 
    727 	val = elm[1].Integer.Value;
    728 
    729 	if (val != 0)
    730 		aprint_debug_dev(sc->sc_dev, "invalid revision in _PSD\n");
    731 
    732 	val = elm[3].Integer.Value;
    733 
    734 	if (val < ACPICPU_DEP_SW_ALL || val > ACPICPU_DEP_HW_ALL) {
    735 		rv = AE_AML_BAD_RESOURCE_VALUE;
    736 		goto out;
    737 	}
    738 
    739 	val = elm[4].Integer.Value;
    740 
    741 	if (val > sc->sc_ncpus) {
    742 		rv = AE_BAD_VALUE;
    743 		goto out;
    744 	}
    745 
    746 	sc->sc_pstate_dep.dep_domain = elm[2].Integer.Value;
    747 	sc->sc_pstate_dep.dep_type   = elm[3].Integer.Value;
    748 	sc->sc_pstate_dep.dep_ncpus  = elm[4].Integer.Value;
    749 
    750 out:
    751 	if (ACPI_FAILURE(rv) && rv != AE_NOT_FOUND)
    752 		aprint_debug_dev(sc->sc_dev, "failed to evaluate "
    753 		    "_PSD: %s\n", AcpiFormatException(rv));
    754 
    755 	if (buf.Pointer != NULL)
    756 		ACPI_FREE(buf.Pointer);
    757 
    758 	return rv;
    759 }
    760 
    761 static int
    762 acpicpu_pstate_max(struct acpicpu_softc *sc)
    763 {
    764 	ACPI_INTEGER val;
    765 	ACPI_STATUS rv;
    766 
    767 	/*
    768 	 * Evaluate the currently highest P-state that can be used.
    769 	 * If available, we can use either this state or any lower
    770 	 * power (i.e. higher numbered) state from the _PSS object.
    771 	 * Note that the return value must match the _OST parameter.
    772 	 */
    773 	rv = acpi_eval_integer(sc->sc_node->ad_handle, "_PPC", &val);
    774 
    775 	if (ACPI_SUCCESS(rv) && val < sc->sc_pstate_count) {
    776 
    777 		if (sc->sc_pstate[val].ps_freq != 0) {
    778 			sc->sc_pstate_max = val;
    779 			return 0;
    780 		}
    781 	}
    782 
    783 	return 1;
    784 }
    785 
    786 static int
    787 acpicpu_pstate_min(struct acpicpu_softc *sc)
    788 {
    789 	ACPI_INTEGER val;
    790 	ACPI_STATUS rv;
    791 
    792 	/*
    793 	 * The _PDL object defines the minimum when passive cooling
    794 	 * is being performed. If available, we can use the returned
    795 	 * state or any higher power (i.e. lower numbered) state.
    796 	 */
    797 	rv = acpi_eval_integer(sc->sc_node->ad_handle, "_PDL", &val);
    798 
    799 	if (ACPI_SUCCESS(rv) && val < sc->sc_pstate_count) {
    800 
    801 		if (sc->sc_pstate[val].ps_freq == 0)
    802 			return 1;
    803 
    804 		if (val >= sc->sc_pstate_max) {
    805 			sc->sc_pstate_min = val;
    806 			return 0;
    807 		}
    808 	}
    809 
    810 	return 1;
    811 }
    812 
    813 static void
    814 acpicpu_pstate_change(struct acpicpu_softc *sc)
    815 {
    816 	static ACPI_STATUS rv = AE_OK;
    817 	ACPI_OBJECT_LIST arg;
    818 	ACPI_OBJECT obj[2];
    819 	static int val = 0;
    820 
    821 	acpicpu_pstate_reset(sc);
    822 
    823 	/*
    824 	 * Cache the checks as the optional
    825 	 * _PDL and _OST are rarely present.
    826 	 */
    827 	if (val == 0)
    828 		val = acpicpu_pstate_min(sc);
    829 
    830 	arg.Count = 2;
    831 	arg.Pointer = obj;
    832 
    833 	obj[0].Type = ACPI_TYPE_INTEGER;
    834 	obj[1].Type = ACPI_TYPE_INTEGER;
    835 
    836 	obj[0].Integer.Value = ACPICPU_P_NOTIFY;
    837 	obj[1].Integer.Value = acpicpu_pstate_max(sc);
    838 
    839 	if (ACPI_FAILURE(rv))
    840 		return;
    841 
    842 	rv = AcpiEvaluateObject(sc->sc_node->ad_handle, "_OST", &arg, NULL);
    843 }
    844 
    845 static void
    846 acpicpu_pstate_reset(struct acpicpu_softc *sc)
    847 {
    848 
    849 	sc->sc_pstate_max = 0;
    850 	sc->sc_pstate_min = sc->sc_pstate_count - 1;
    851 
    852 }
    853 
    854 static void
    855 acpicpu_pstate_bios(void)
    856 {
    857 	const uint8_t val = AcpiGbl_FADT.PstateControl;
    858 	const uint32_t addr = AcpiGbl_FADT.SmiCommand;
    859 
    860 	if (addr == 0 || val == 0)
    861 		return;
    862 
    863 	(void)AcpiOsWritePort(addr, val, 8);
    864 }
    865 
    866 int
    867 acpicpu_pstate_get(struct cpu_info *ci, uint32_t *freq)
    868 {
    869 	struct acpicpu_pstate *ps = NULL;
    870 	struct acpicpu_softc *sc;
    871 	uint32_t i, val = 0;
    872 	uint64_t addr;
    873 	uint8_t width;
    874 	int rv;
    875 
    876 	sc = acpicpu_sc[ci->ci_acpiid];
    877 
    878 	if (__predict_false(sc == NULL)) {
    879 		rv = ENXIO;
    880 		goto fail;
    881 	}
    882 
    883 	if (__predict_false(sc->sc_cold != false)) {
    884 		rv = EBUSY;
    885 		goto fail;
    886 	}
    887 
    888 	if (__predict_false((sc->sc_flags & ACPICPU_FLAG_P) == 0)) {
    889 		rv = ENODEV;
    890 		goto fail;
    891 	}
    892 
    893 	mutex_enter(&sc->sc_mtx);
    894 
    895 	/*
    896 	 * Use the cached value, if available.
    897 	 */
    898 	if (sc->sc_pstate_current != ACPICPU_P_STATE_UNKNOWN) {
    899 		*freq = sc->sc_pstate_current;
    900 		mutex_exit(&sc->sc_mtx);
    901 		return 0;
    902 	}
    903 
    904 	mutex_exit(&sc->sc_mtx);
    905 
    906 	switch (sc->sc_pstate_status.reg_spaceid) {
    907 
    908 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
    909 
    910 		rv = acpicpu_md_pstate_get(sc, freq);
    911 
    912 		if (__predict_false(rv != 0))
    913 			goto fail;
    914 
    915 		break;
    916 
    917 	case ACPI_ADR_SPACE_SYSTEM_IO:
    918 
    919 		addr  = sc->sc_pstate_status.reg_addr;
    920 		width = sc->sc_pstate_status.reg_bitwidth;
    921 
    922 		(void)AcpiOsReadPort(addr, &val, width);
    923 
    924 		if (val == 0) {
    925 			rv = EIO;
    926 			goto fail;
    927 		}
    928 
    929 		for (i = 0; i < sc->sc_pstate_count; i++) {
    930 
    931 			if (sc->sc_pstate[i].ps_freq == 0)
    932 				continue;
    933 
    934 			if (val == sc->sc_pstate[i].ps_status) {
    935 				ps = &sc->sc_pstate[i];
    936 				break;
    937 			}
    938 		}
    939 
    940 		if (ps == NULL) {
    941 			rv = EIO;
    942 			goto fail;
    943 		}
    944 
    945 		*freq = ps->ps_freq;
    946 		break;
    947 
    948 	default:
    949 		rv = ENOTTY;
    950 		goto fail;
    951 	}
    952 
    953 	mutex_enter(&sc->sc_mtx);
    954 	sc->sc_pstate_current = *freq;
    955 	mutex_exit(&sc->sc_mtx);
    956 
    957 	return 0;
    958 
    959 fail:
    960 	aprint_error_dev(sc->sc_dev, "failed "
    961 	    "to get frequency (err %d)\n", rv);
    962 
    963 	mutex_enter(&sc->sc_mtx);
    964 	*freq = sc->sc_pstate_current = ACPICPU_P_STATE_UNKNOWN;
    965 	mutex_exit(&sc->sc_mtx);
    966 
    967 	return rv;
    968 }
    969 
    970 void
    971 acpicpu_pstate_set(struct cpu_info *ci, uint32_t freq)
    972 {
    973 	uint64_t xc;
    974 
    975 	xc = xc_broadcast(0, acpicpu_pstate_set_xcall, &freq, NULL);
    976 	xc_wait(xc);
    977 }
    978 
    979 static void
    980 acpicpu_pstate_set_xcall(void *arg1, void *arg2)
    981 {
    982 	struct acpicpu_pstate *ps = NULL;
    983 	struct cpu_info *ci = curcpu();
    984 	struct acpicpu_softc *sc;
    985 	uint32_t freq, i, val;
    986 	uint64_t addr;
    987 	uint8_t width;
    988 	int rv;
    989 
    990 	freq = *(uint32_t *)arg1;
    991 	sc = acpicpu_sc[ci->ci_acpiid];
    992 
    993 	if (__predict_false(sc == NULL)) {
    994 		rv = ENXIO;
    995 		goto fail;
    996 	}
    997 
    998 	if (__predict_false(sc->sc_cold != false)) {
    999 		rv = EBUSY;
   1000 		goto fail;
   1001 	}
   1002 
   1003 	if (__predict_false((sc->sc_flags & ACPICPU_FLAG_P) == 0)) {
   1004 		rv = ENODEV;
   1005 		goto fail;
   1006 	}
   1007 
   1008 	mutex_enter(&sc->sc_mtx);
   1009 
   1010 	if (sc->sc_pstate_current == freq) {
   1011 		mutex_exit(&sc->sc_mtx);
   1012 		return;
   1013 	}
   1014 
   1015 	/*
   1016 	 * Verify that the requested frequency is available.
   1017 	 *
   1018 	 * The access needs to be protected since the currently
   1019 	 * available maximum and minimum may change dynamically.
   1020 	 */
   1021 	for (i = sc->sc_pstate_max; i <= sc->sc_pstate_min; i++) {
   1022 
   1023 		if (__predict_false(sc->sc_pstate[i].ps_freq == 0))
   1024 			continue;
   1025 
   1026 		if (sc->sc_pstate[i].ps_freq == freq) {
   1027 			ps = &sc->sc_pstate[i];
   1028 			break;
   1029 		}
   1030 	}
   1031 
   1032 	mutex_exit(&sc->sc_mtx);
   1033 
   1034 	if (__predict_false(ps == NULL)) {
   1035 		rv = EINVAL;
   1036 		goto fail;
   1037 	}
   1038 
   1039 	switch (sc->sc_pstate_control.reg_spaceid) {
   1040 
   1041 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
   1042 
   1043 		rv = acpicpu_md_pstate_set(ps);
   1044 
   1045 		if (__predict_false(rv != 0))
   1046 			goto fail;
   1047 
   1048 		break;
   1049 
   1050 	case ACPI_ADR_SPACE_SYSTEM_IO:
   1051 
   1052 		addr  = sc->sc_pstate_control.reg_addr;
   1053 		width = sc->sc_pstate_control.reg_bitwidth;
   1054 
   1055 		(void)AcpiOsWritePort(addr, ps->ps_control, width);
   1056 
   1057 		addr  = sc->sc_pstate_status.reg_addr;
   1058 		width = sc->sc_pstate_status.reg_bitwidth;
   1059 
   1060 		/*
   1061 		 * Some systems take longer to respond
   1062 		 * than the reported worst-case latency.
   1063 		 */
   1064 		for (i = val = 0; i < ACPICPU_P_STATE_RETRY; i++) {
   1065 
   1066 			(void)AcpiOsReadPort(addr, &val, width);
   1067 
   1068 			if (val == ps->ps_status)
   1069 				break;
   1070 
   1071 			DELAY(ps->ps_latency);
   1072 		}
   1073 
   1074 		if (i == ACPICPU_P_STATE_RETRY) {
   1075 			rv = EAGAIN;
   1076 			goto fail;
   1077 		}
   1078 
   1079 		break;
   1080 
   1081 	default:
   1082 		rv = ENOTTY;
   1083 		goto fail;
   1084 	}
   1085 
   1086 	mutex_enter(&sc->sc_mtx);
   1087 	ps->ps_evcnt.ev_count++;
   1088 	sc->sc_pstate_current = freq;
   1089 	mutex_exit(&sc->sc_mtx);
   1090 
   1091 	return;
   1092 
   1093 fail:
   1094 	aprint_error_dev(sc->sc_dev, "failed to set "
   1095 	    "frequency to %u (err %d)\n", freq, rv);
   1096 
   1097 	mutex_enter(&sc->sc_mtx);
   1098 	sc->sc_pstate_current = ACPICPU_P_STATE_UNKNOWN;
   1099 	mutex_exit(&sc->sc_mtx);
   1100 }
   1101