acpi_cpu_tstate.c revision 1.10
1 /* $NetBSD: acpi_cpu_tstate.c,v 1.10 2010/08/16 04:31:21 jruoho Exp $ */ 2 3 /*- 4 * Copyright (c) 2010 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_tstate.c,v 1.10 2010/08/16 04:31:21 jruoho Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/evcnt.h> 34 #include <sys/kmem.h> 35 36 #include <dev/acpi/acpireg.h> 37 #include <dev/acpi/acpivar.h> 38 #include <dev/acpi/acpi_cpu.h> 39 40 #define _COMPONENT ACPI_BUS_COMPONENT 41 ACPI_MODULE_NAME ("acpi_cpu_tstate") 42 43 static void acpicpu_tstate_attach_print(struct acpicpu_softc *); 44 static void acpicpu_tstate_attach_evcnt(struct acpicpu_softc *); 45 static void acpicpu_tstate_detach_evcnt(struct acpicpu_softc *); 46 static ACPI_STATUS acpicpu_tstate_tss(struct acpicpu_softc *); 47 static ACPI_STATUS acpicpu_tstate_tss_add(struct acpicpu_tstate *, 48 ACPI_OBJECT *); 49 static ACPI_STATUS acpicpu_tstate_ptc(struct acpicpu_softc *); 50 static ACPI_STATUS acpicpu_tstate_fadt(struct acpicpu_softc *); 51 static ACPI_STATUS acpicpu_tstate_change(struct acpicpu_softc *); 52 53 void 54 acpicpu_tstate_attach(device_t self) 55 { 56 struct acpicpu_softc *sc = device_private(self); 57 const char *str; 58 ACPI_STATUS rv; 59 60 /* 61 * Disable T-states for PIIX4. 62 */ 63 if ((sc->sc_flags & ACPICPU_FLAG_PIIX4) != 0) 64 return; 65 66 rv = acpicpu_tstate_tss(sc); 67 68 if (ACPI_FAILURE(rv)) { 69 str = "_TSS"; 70 goto out; 71 } 72 73 rv = acpicpu_tstate_ptc(sc); 74 75 if (ACPI_FAILURE(rv)) { 76 str = "_PTC"; 77 goto out; 78 } 79 80 /* 81 * Comparable to P-states, the _TPC object may 82 * be absent in some systems, even though it is 83 * required by ACPI 3.0 along with _TSS and _PTC. 84 */ 85 (void)acpicpu_tstate_change(sc); 86 87 out: 88 if (ACPI_FAILURE(rv)) { 89 90 if (rv != AE_NOT_FOUND) 91 aprint_error_dev(sc->sc_dev, "failed to evaluate " 92 "%s: %s\n", str, AcpiFormatException(rv)); 93 94 rv = acpicpu_tstate_fadt(sc); 95 96 if (ACPI_FAILURE(rv)) 97 return; 98 99 sc->sc_flags |= ACPICPU_FLAG_T_FADT; 100 } 101 102 sc->sc_flags |= ACPICPU_FLAG_T; 103 104 acpicpu_tstate_attach_evcnt(sc); 105 acpicpu_tstate_attach_print(sc); 106 } 107 108 static void 109 acpicpu_tstate_attach_print(struct acpicpu_softc *sc) 110 { 111 const uint8_t method = sc->sc_tstate_control.reg_spaceid; 112 struct acpicpu_tstate *ts; 113 static bool once = false; 114 const char *str; 115 uint32_t i; 116 117 if (once != false) 118 return; 119 120 str = (method != ACPI_ADR_SPACE_FIXED_HARDWARE) ? "I/O" : "FFH"; 121 122 for (i = 0; i < sc->sc_tstate_count; i++) { 123 124 ts = &sc->sc_tstate[i]; 125 126 if (ts->ts_percent == 0) 127 continue; 128 129 aprint_debug_dev(sc->sc_dev, "T%u: %3s, " 130 "lat %3u us, pow %5u mW, %3u %%\n", i, str, 131 ts->ts_latency, ts->ts_power, ts->ts_percent); 132 } 133 134 once = true; 135 } 136 137 static void 138 acpicpu_tstate_attach_evcnt(struct acpicpu_softc *sc) 139 { 140 struct acpicpu_tstate *ts; 141 uint32_t i; 142 143 for (i = 0; i < sc->sc_tstate_count; i++) { 144 145 ts = &sc->sc_tstate[i]; 146 147 if (ts->ts_percent == 0) 148 continue; 149 150 (void)snprintf(ts->ts_name, sizeof(ts->ts_name), 151 "T%u (%u %%)", i, ts->ts_percent); 152 153 evcnt_attach_dynamic(&ts->ts_evcnt, EVCNT_TYPE_MISC, 154 NULL, device_xname(sc->sc_dev), ts->ts_name); 155 } 156 } 157 158 int 159 acpicpu_tstate_detach(device_t self) 160 { 161 struct acpicpu_softc *sc = device_private(self); 162 size_t size; 163 164 if ((sc->sc_flags & ACPICPU_FLAG_T) == 0) 165 return 0; 166 167 size = sc->sc_tstate_count * sizeof(*sc->sc_tstate); 168 169 if (sc->sc_tstate != NULL) 170 kmem_free(sc->sc_tstate, size); 171 172 sc->sc_flags &= ~ACPICPU_FLAG_T; 173 acpicpu_tstate_detach_evcnt(sc); 174 175 return 0; 176 } 177 178 static void 179 acpicpu_tstate_detach_evcnt(struct acpicpu_softc *sc) 180 { 181 struct acpicpu_tstate *ts; 182 uint32_t i; 183 184 for (i = 0; i < sc->sc_tstate_count; i++) { 185 186 ts = &sc->sc_tstate[i]; 187 188 if (ts->ts_percent != 0) 189 evcnt_detach(&ts->ts_evcnt); 190 } 191 } 192 193 int 194 acpicpu_tstate_start(device_t self) 195 { 196 197 return 0; 198 } 199 200 bool 201 acpicpu_tstate_suspend(device_t self) 202 { 203 204 return true; 205 } 206 207 bool 208 acpicpu_tstate_resume(device_t self) 209 { 210 struct acpicpu_softc *sc = device_private(self); 211 212 if ((sc->sc_flags & ACPICPU_FLAG_T_FADT) == 0) 213 acpicpu_tstate_callback(self); 214 215 return true; 216 } 217 218 void 219 acpicpu_tstate_callback(void *aux) 220 { 221 struct acpicpu_softc *sc; 222 device_t self = aux; 223 uint32_t omax, omin; 224 int i; 225 226 sc = device_private(self); 227 228 if ((sc->sc_flags & ACPICPU_FLAG_T_FADT) != 0) 229 return; 230 231 mutex_enter(&sc->sc_mtx); 232 233 /* 234 * If P-states are in use, we should ignore 235 * the interrupt unless we are in the highest 236 * P-state (see ACPI 4.0, section 8.4.3.3). 237 */ 238 if ((sc->sc_flags & ACPICPU_FLAG_P) != 0) { 239 240 for (i = sc->sc_pstate_count - 1; i >= 0; i--) { 241 242 if (sc->sc_pstate[i].ps_freq != 0) 243 break; 244 } 245 246 if (sc->sc_pstate_current != sc->sc_pstate[i].ps_freq) { 247 mutex_exit(&sc->sc_mtx); 248 return; 249 } 250 } 251 252 omax = sc->sc_tstate_max; 253 omin = sc->sc_tstate_min; 254 255 (void)acpicpu_tstate_change(sc); 256 257 if (omax != sc->sc_tstate_max || omin != sc->sc_tstate_min) { 258 259 aprint_debug_dev(sc->sc_dev, "throttling window " 260 "changed from %u-%u %% to %u-%u %%\n", 261 sc->sc_tstate[omax].ts_percent, 262 sc->sc_tstate[omin].ts_percent, 263 sc->sc_tstate[sc->sc_tstate_max].ts_percent, 264 sc->sc_tstate[sc->sc_tstate_min].ts_percent); 265 } 266 267 mutex_exit(&sc->sc_mtx); 268 } 269 270 static ACPI_STATUS 271 acpicpu_tstate_tss(struct acpicpu_softc *sc) 272 { 273 struct acpicpu_tstate *ts; 274 ACPI_OBJECT *obj; 275 ACPI_BUFFER buf; 276 ACPI_STATUS rv; 277 uint32_t count; 278 uint32_t i, j; 279 280 rv = acpi_eval_struct(sc->sc_node->ad_handle, "_TSS", &buf); 281 282 if (ACPI_FAILURE(rv)) 283 return rv; 284 285 obj = buf.Pointer; 286 287 if (obj->Type != ACPI_TYPE_PACKAGE) { 288 rv = AE_TYPE; 289 goto out; 290 } 291 292 sc->sc_tstate_count = obj->Package.Count; 293 294 if (sc->sc_tstate_count == 0) { 295 rv = AE_NOT_EXIST; 296 goto out; 297 } 298 299 if (sc->sc_tstate_count > ACPICPU_T_STATE_MAX) { 300 rv = AE_LIMIT; 301 goto out; 302 } 303 304 sc->sc_tstate = kmem_zalloc(sc->sc_tstate_count * 305 sizeof(struct acpicpu_tstate), KM_SLEEP); 306 307 if (sc->sc_tstate == NULL) { 308 rv = AE_NO_MEMORY; 309 goto out; 310 } 311 312 for (count = i = 0; i < sc->sc_tstate_count; i++) { 313 314 ts = &sc->sc_tstate[i]; 315 rv = acpicpu_tstate_tss_add(ts, &obj->Package.Elements[i]); 316 317 if (ACPI_FAILURE(rv)) { 318 ts->ts_percent = 0; 319 continue; 320 } 321 322 for (j = 0; j < i; j++) { 323 324 if (ts->ts_percent >= sc->sc_tstate[j].ts_percent) { 325 ts->ts_percent = 0; 326 break; 327 } 328 } 329 330 if (ts->ts_percent != 0) 331 count++; 332 } 333 334 if (count == 0) { 335 rv = AE_NOT_EXIST; 336 goto out; 337 } 338 339 /* 340 * There must be an entry with the percent 341 * field of 100. If this is not true, and if 342 * this entry is not in the expected index, 343 * invalidate the use of T-states via _TSS. 344 */ 345 if (sc->sc_tstate[0].ts_percent != 100) { 346 rv = AE_BAD_DECIMAL_CONSTANT; 347 goto out; 348 } 349 350 /* 351 * The first entry with 100 % duty cycle 352 * should have zero in the control field. 353 */ 354 if (sc->sc_tstate[0].ts_control != 0) { 355 rv = AE_AML_BAD_RESOURCE_VALUE; 356 goto out; 357 } 358 359 out: 360 if (buf.Pointer != NULL) 361 ACPI_FREE(buf.Pointer); 362 363 return rv; 364 } 365 366 static ACPI_STATUS 367 acpicpu_tstate_tss_add(struct acpicpu_tstate *ts, ACPI_OBJECT *obj) 368 { 369 ACPI_OBJECT *elm; 370 uint32_t val[5]; 371 uint32_t *p; 372 int i; 373 374 if (obj->Type != ACPI_TYPE_PACKAGE) 375 return AE_TYPE; 376 377 if (obj->Package.Count != 5) 378 return AE_BAD_DATA; 379 380 elm = obj->Package.Elements; 381 382 for (i = 0; i < 5; i++) { 383 384 if (elm[i].Type != ACPI_TYPE_INTEGER) 385 return AE_TYPE; 386 387 if (elm[i].Integer.Value > UINT32_MAX) 388 return AE_AML_NUMERIC_OVERFLOW; 389 390 val[i] = elm[i].Integer.Value; 391 } 392 393 p = &ts->ts_percent; 394 395 for (i = 0; i < 5; i++, p++) 396 *p = val[i]; 397 398 /* 399 * The minimum should be around 100 / 8 = 12.5 %. 400 */ 401 if (ts->ts_percent < 10 || ts->ts_percent > 100) 402 return AE_BAD_DECIMAL_CONSTANT; 403 404 if (ts->ts_latency < 1) 405 ts->ts_latency = 1; 406 407 return AE_OK; 408 } 409 410 ACPI_STATUS 411 acpicpu_tstate_ptc(struct acpicpu_softc *sc) 412 { 413 static const size_t size = sizeof(struct acpicpu_reg); 414 struct acpicpu_reg *reg[2]; 415 ACPI_OBJECT *elm, *obj; 416 ACPI_BUFFER buf; 417 ACPI_STATUS rv; 418 int i; 419 420 rv = acpi_eval_struct(sc->sc_node->ad_handle, "_PTC", &buf); 421 422 if (ACPI_FAILURE(rv)) 423 return rv; 424 425 obj = buf.Pointer; 426 427 if (obj->Type != ACPI_TYPE_PACKAGE) { 428 rv = AE_TYPE; 429 goto out; 430 } 431 432 if (obj->Package.Count != 2) { 433 rv = AE_LIMIT; 434 goto out; 435 } 436 437 for (i = 0; i < 2; i++) { 438 439 elm = &obj->Package.Elements[i]; 440 441 if (elm->Type != ACPI_TYPE_BUFFER) { 442 rv = AE_TYPE; 443 goto out; 444 } 445 446 if (size > elm->Buffer.Length) { 447 rv = AE_AML_BAD_RESOURCE_LENGTH; 448 goto out; 449 } 450 451 reg[i] = (struct acpicpu_reg *)elm->Buffer.Pointer; 452 453 switch (reg[i]->reg_spaceid) { 454 455 case ACPI_ADR_SPACE_SYSTEM_IO: 456 457 if (reg[i]->reg_addr == 0) { 458 rv = AE_AML_ILLEGAL_ADDRESS; 459 goto out; 460 } 461 462 /* 463 * Check that the values match the IA32 clock 464 * modulation MSR, where the bit 0 is reserved, 465 * bits 1 through 3 define the duty cycle, and 466 * the fourth bit enables the modulation. 467 */ 468 if (reg[i]->reg_bitwidth != 4) { 469 rv = AE_AML_BAD_RESOURCE_VALUE; 470 goto out; 471 } 472 473 if (reg[i]->reg_bitoffset != 1) { 474 rv = AE_AML_BAD_RESOURCE_VALUE; 475 goto out; 476 } 477 478 break; 479 480 case ACPI_ADR_SPACE_FIXED_HARDWARE: 481 482 if ((sc->sc_flags & ACPICPU_FLAG_T_FFH) == 0) { 483 rv = AE_SUPPORT; 484 goto out; 485 } 486 487 break; 488 489 default: 490 rv = AE_AML_INVALID_SPACE_ID; 491 goto out; 492 } 493 } 494 495 if (reg[0]->reg_spaceid != reg[1]->reg_spaceid) { 496 rv = AE_AML_INVALID_SPACE_ID; 497 goto out; 498 } 499 500 (void)memcpy(&sc->sc_tstate_control, reg[0], size); 501 (void)memcpy(&sc->sc_tstate_status, reg[1], size); 502 503 out: 504 if (buf.Pointer != NULL) 505 ACPI_FREE(buf.Pointer); 506 507 return rv; 508 } 509 510 static ACPI_STATUS 511 acpicpu_tstate_fadt(struct acpicpu_softc *sc) 512 { 513 static const size_t size = sizeof(struct acpicpu_tstate); 514 const uint8_t offset = AcpiGbl_FADT.DutyOffset; 515 const uint8_t width = AcpiGbl_FADT.DutyWidth; 516 uint8_t beta, count, i; 517 518 if (sc->sc_object.ao_pblkaddr == 0) 519 return AE_AML_ILLEGAL_ADDRESS; 520 521 /* 522 * A zero DUTY_WIDTH is used announce that 523 * T-states are not available via FADT. 524 */ 525 if (width == 0 || width + offset > 4) 526 return AE_AML_BAD_RESOURCE_VALUE; 527 528 count = 1 << width; 529 530 if (count > ACPICPU_T_STATE_MAX) 531 return AE_LIMIT; 532 533 if (sc->sc_tstate != NULL) 534 kmem_free(sc->sc_tstate, sc->sc_tstate_count * size); 535 536 sc->sc_tstate = kmem_zalloc(count * size, KM_SLEEP); 537 538 if (sc->sc_tstate == NULL) 539 return ENOMEM; 540 541 sc->sc_tstate_count = count; 542 543 /* 544 * Approximate duty cycles and set the MSR values. 545 */ 546 for (beta = 100 / count, i = 0; i < count; i++) { 547 sc->sc_tstate[i].ts_percent = 100 - beta * i; 548 sc->sc_tstate[i].ts_latency = 1; 549 } 550 551 for (i = 1; i < count; i++) 552 sc->sc_tstate[i].ts_control = (count - i) | __BIT(3); 553 554 /* 555 * Fake values for throttling registers. 556 */ 557 (void)memset(&sc->sc_tstate_status, 0, sizeof(struct acpicpu_reg)); 558 (void)memset(&sc->sc_tstate_control, 0, sizeof(struct acpicpu_reg)); 559 560 sc->sc_tstate_status.reg_bitwidth = width; 561 sc->sc_tstate_status.reg_bitoffset = offset; 562 sc->sc_tstate_status.reg_addr = sc->sc_object.ao_pblkaddr; 563 sc->sc_tstate_status.reg_spaceid = ACPI_ADR_SPACE_SYSTEM_IO; 564 565 sc->sc_tstate_control.reg_bitwidth = width; 566 sc->sc_tstate_control.reg_bitoffset = offset; 567 sc->sc_tstate_control.reg_addr = sc->sc_object.ao_pblkaddr; 568 sc->sc_tstate_control.reg_spaceid = ACPI_ADR_SPACE_SYSTEM_IO; 569 570 return AE_OK; 571 } 572 573 static ACPI_STATUS 574 acpicpu_tstate_change(struct acpicpu_softc *sc) 575 { 576 ACPI_INTEGER val; 577 ACPI_STATUS rv; 578 579 sc->sc_tstate_max = 0; 580 sc->sc_tstate_min = sc->sc_tstate_count - 1; 581 582 /* 583 * Evaluate the available T-state window: 584 * 585 * _TPC : either this maximum or any lower power 586 * (i.e. higher numbered) state may be used. 587 * 588 * _TDL : either this minimum or any higher power 589 * (i.e. lower numbered) state may be used. 590 * 591 * _TDL >= _TPC || _TDL >= _TSS[last entry]. 592 */ 593 rv = acpi_eval_integer(sc->sc_node->ad_handle, "_TPC", &val); 594 595 if (ACPI_FAILURE(rv)) 596 return rv; 597 598 if (val < sc->sc_tstate_count) { 599 600 if (sc->sc_tstate[val].ts_percent != 0) 601 sc->sc_tstate_max = val; 602 } 603 604 rv = acpi_eval_integer(sc->sc_node->ad_handle, "_TDL", &val); 605 606 if (ACPI_SUCCESS(rv) && val < sc->sc_tstate_count) { 607 608 if (val >= sc->sc_tstate_max && 609 sc->sc_tstate[val].ts_percent != 0) 610 sc->sc_tstate_min = val; 611 } 612 613 return AE_OK; 614 } 615 616 int 617 acpicpu_tstate_get(struct acpicpu_softc *sc, uint32_t *percent) 618 { 619 const uint8_t method = sc->sc_tstate_control.reg_spaceid; 620 struct acpicpu_tstate *ts = NULL; 621 uint32_t i, val = 0; 622 uint8_t offset; 623 uint64_t addr; 624 int rv; 625 626 if (sc->sc_cold != false) { 627 rv = EBUSY; 628 goto fail; 629 } 630 631 if ((sc->sc_flags & ACPICPU_FLAG_T) == 0) { 632 rv = ENODEV; 633 goto fail; 634 } 635 636 mutex_enter(&sc->sc_mtx); 637 638 if (sc->sc_tstate_current != ACPICPU_T_STATE_UNKNOWN) { 639 *percent = sc->sc_tstate_current; 640 mutex_exit(&sc->sc_mtx); 641 return 0; 642 } 643 644 mutex_exit(&sc->sc_mtx); 645 646 switch (method) { 647 648 case ACPI_ADR_SPACE_FIXED_HARDWARE: 649 650 rv = acpicpu_md_tstate_get(sc, percent); 651 652 if (rv != 0) 653 goto fail; 654 655 break; 656 657 case ACPI_ADR_SPACE_SYSTEM_IO: 658 659 addr = sc->sc_tstate_status.reg_addr; 660 offset = sc->sc_tstate_status.reg_bitoffset; 661 662 (void)AcpiOsReadPort(addr, &val, 8); 663 664 val = (val >> offset) & 0x0F; 665 666 for (i = 0; i < sc->sc_tstate_count; i++) { 667 668 if (sc->sc_tstate[i].ts_percent == 0) 669 continue; 670 671 /* 672 * As the status field may be zero, compare 673 * against the control field value as well. 674 */ 675 if (val == sc->sc_tstate[i].ts_control) { 676 ts = &sc->sc_tstate[i]; 677 break; 678 } 679 680 if (val == sc->sc_tstate[i].ts_status) { 681 ts = &sc->sc_tstate[i]; 682 break; 683 } 684 } 685 686 if (__predict_false(ts == NULL)) { 687 rv = EIO; 688 goto fail; 689 } 690 691 *percent = ts->ts_percent; 692 break; 693 694 default: 695 rv = ENOTTY; 696 goto fail; 697 } 698 699 mutex_enter(&sc->sc_mtx); 700 sc->sc_tstate_current = *percent; 701 mutex_exit(&sc->sc_mtx); 702 703 return 0; 704 705 fail: 706 aprint_error_dev(sc->sc_dev, "failed " 707 "to get T-state (err %d)\n", rv); 708 709 mutex_enter(&sc->sc_mtx); 710 *percent = sc->sc_tstate_current = ACPICPU_T_STATE_UNKNOWN; 711 mutex_exit(&sc->sc_mtx); 712 713 return rv; 714 } 715 716 int 717 acpicpu_tstate_set(struct acpicpu_softc *sc, uint32_t percent) 718 { 719 const uint8_t method = sc->sc_tstate_control.reg_spaceid; 720 struct acpicpu_tstate *ts = NULL; 721 uint32_t i, val; 722 uint8_t offset; 723 uint64_t addr; 724 int rv; 725 726 if (sc->sc_cold != false) { 727 rv = EBUSY; 728 goto fail; 729 } 730 731 if ((sc->sc_flags & ACPICPU_FLAG_T) == 0) { 732 rv = ENODEV; 733 goto fail; 734 } 735 736 mutex_enter(&sc->sc_mtx); 737 738 for (i = sc->sc_tstate_max; i <= sc->sc_tstate_min; i++) { 739 740 if (sc->sc_tstate[i].ts_percent == 0) 741 continue; 742 743 if (sc->sc_tstate[i].ts_percent == percent) { 744 ts = &sc->sc_tstate[i]; 745 break; 746 } 747 } 748 749 mutex_exit(&sc->sc_mtx); 750 751 if (__predict_false(ts == NULL)) { 752 rv = EINVAL; 753 goto fail; 754 } 755 756 switch (method) { 757 758 case ACPI_ADR_SPACE_FIXED_HARDWARE: 759 760 rv = acpicpu_md_tstate_set(ts); 761 762 if (rv != 0) 763 goto fail; 764 765 break; 766 767 case ACPI_ADR_SPACE_SYSTEM_IO: 768 769 addr = sc->sc_tstate_control.reg_addr; 770 offset = sc->sc_tstate_control.reg_bitoffset; 771 772 val = (ts->ts_control & 0x0F) << offset; 773 774 if (ts->ts_percent != 100 && (val & __BIT(4)) == 0) { 775 rv = EINVAL; 776 goto fail; 777 } 778 779 (void)AcpiOsWritePort(addr, val, 8); 780 781 /* 782 * If the status field is zero, the transition is 783 * specified to be "asynchronous" and there is no 784 * need to check the status (ACPI 4.0, 8.4.3.2). 785 */ 786 if (ts->ts_status == 0) 787 break; 788 789 addr = sc->sc_tstate_status.reg_addr; 790 offset = sc->sc_tstate_status.reg_bitoffset; 791 792 for (i = val = 0; i < ACPICPU_T_STATE_RETRY; i++) { 793 794 (void)AcpiOsReadPort(addr, &val, 8); 795 796 val = (val >> offset) & 0x0F; 797 798 if (val == ts->ts_status) 799 break; 800 801 DELAY(ts->ts_latency); 802 } 803 804 if (i == ACPICPU_T_STATE_RETRY) { 805 rv = EAGAIN; 806 goto fail; 807 } 808 809 break; 810 811 default: 812 rv = ENOTTY; 813 goto fail; 814 } 815 816 mutex_enter(&sc->sc_mtx); 817 ts->ts_evcnt.ev_count++; 818 sc->sc_tstate_current = percent; 819 mutex_exit(&sc->sc_mtx); 820 821 return 0; 822 823 fail: 824 aprint_error_dev(sc->sc_dev, "failed to " 825 "throttle to %u %% (err %d)\n", percent, rv); 826 827 mutex_enter(&sc->sc_mtx); 828 sc->sc_tstate_current = ACPICPU_T_STATE_UNKNOWN; 829 mutex_exit(&sc->sc_mtx); 830 831 return rv; 832 } 833
Indexes created Tue Sep 23 07:09:52 GMT 2025