1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * AMD K7 Powernow driver. 4 * (C) 2003 Dave Jones on behalf of SuSE Labs. 5 * 6 * Based upon datasheets & sample CPUs kindly provided by AMD. 7 * 8 * Errata 5: 9 * CPU may fail to execute a FID/VID change in presence of interrupt. 10 * - We cli/sti on stepping A0 CPUs around the FID/VID transition. 11 * Errata 15: 12 * CPU with half frequency multipliers may hang upon wakeup from disconnect. 13 * - We disable half multipliers if ACPI is used on A0 stepping CPUs. 14 */ 15 16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 17 18 #include <linux/kernel.h> 19 #include <linux/module.h> 20 #include <linux/moduleparam.h> 21 #include <linux/init.h> 22 #include <linux/cpufreq.h> 23 #include <linux/slab.h> 24 #include <linux/string.h> 25 #include <linux/dmi.h> 26 #include <linux/timex.h> 27 #include <linux/io.h> 28 29 #include <asm/timer.h> /* Needed for recalibrate_cpu_khz() */ 30 #include <asm/msr.h> 31 #include <asm/cpu_device_id.h> 32 33 #ifdef CONFIG_X86_POWERNOW_K7_ACPI 34 #include <linux/acpi.h> 35 #include <acpi/processor.h> 36 #endif 37 38 #include "powernow-k7.h" 39 40 struct psb_s { 41 u8 signature[10]; 42 u8 tableversion; 43 u8 flags; 44 u16 settlingtime; 45 u8 reserved1; 46 u8 numpst; 47 }; 48 49 struct pst_s { 50 u32 cpuid; 51 u8 fsbspeed; 52 u8 maxfid; 53 u8 startvid; 54 u8 numpstates; 55 }; 56 57 #ifdef CONFIG_X86_POWERNOW_K7_ACPI 58 union powernow_acpi_control_t { 59 struct { 60 unsigned long fid:5, 61 vid:5, 62 sgtc:20, 63 res1:2; 64 } bits; 65 unsigned long val; 66 }; 67 #endif 68 69 /* divide by 1000 to get VCore voltage in V. */ 70 static const int mobile_vid_table[32] = { 71 2000, 1950, 1900, 1850, 1800, 1750, 1700, 1650, 72 1600, 1550, 1500, 1450, 1400, 1350, 1300, 0, 73 1275, 1250, 1225, 1200, 1175, 1150, 1125, 1100, 74 1075, 1050, 1025, 1000, 975, 950, 925, 0, 75 }; 76 77 /* divide by 10 to get FID. */ 78 static const int fid_codes[32] = { 79 110, 115, 120, 125, 50, 55, 60, 65, 80 70, 75, 80, 85, 90, 95, 100, 105, 81 30, 190, 40, 200, 130, 135, 140, 210, 82 150, 225, 160, 165, 170, 180, -1, -1, 83 }; 84 85 /* This parameter is used in order to force ACPI instead of legacy method for 86 * configuration purpose. 87 */ 88 89 static int acpi_force; 90 91 static struct cpufreq_frequency_table *powernow_table; 92 93 static unsigned int can_scale_bus; 94 static unsigned int can_scale_vid; 95 static unsigned int minimum_speed = -1; 96 static unsigned int maximum_speed; 97 static unsigned int number_scales; 98 static unsigned int fsb; 99 static unsigned int latency; 100 static char have_a0; 101 102 static int check_fsb(unsigned int fsbspeed) 103 { 104 int delta; 105 unsigned int f = fsb / 1000; 106 107 delta = (fsbspeed > f) ? fsbspeed - f : f - fsbspeed; 108 return delta < 5; 109 } 110 111 static const struct x86_cpu_id powernow_k7_cpuids[] = { 112 X86_MATCH_VENDOR_FAM(AMD, 6, NULL), 113 {} 114 }; 115 MODULE_DEVICE_TABLE(x86cpu, powernow_k7_cpuids); 116 117 static int check_powernow(void) 118 { 119 struct cpuinfo_x86 *c = &cpu_data(0); 120 unsigned int maxei, eax, ebx, ecx, edx; 121 122 if (!x86_match_cpu(powernow_k7_cpuids)) 123 return 0; 124 125 /* Get maximum capabilities */ 126 maxei = cpuid_eax(0x80000000); 127 if (maxei < 0x80000007) { /* Any powernow info ? */ 128 #ifdef MODULE 129 pr_info("No powernow capabilities detected\n"); 130 #endif 131 return 0; 132 } 133 134 if ((c->x86_model == 6) && (c->x86_stepping == 0)) { 135 pr_info("K7 660[A0] core detected, enabling errata workarounds\n"); 136 have_a0 = 1; 137 } 138 139 cpuid(0x80000007, &eax, &ebx, &ecx, &edx); 140 141 /* Check we can actually do something before we say anything.*/ 142 if (!(edx & (1 << 1 | 1 << 2))) 143 return 0; 144 145 pr_info("PowerNOW! Technology present. Can scale: "); 146 147 if (edx & 1 << 1) { 148 pr_cont("frequency"); 149 can_scale_bus = 1; 150 } 151 152 if ((edx & (1 << 1 | 1 << 2)) == 0x6) 153 pr_cont(" and "); 154 155 if (edx & 1 << 2) { 156 pr_cont("voltage"); 157 can_scale_vid = 1; 158 } 159 160 pr_cont("\n"); 161 return 1; 162 } 163 164 #ifdef CONFIG_X86_POWERNOW_K7_ACPI 165 static void invalidate_entry(unsigned int entry) 166 { 167 powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID; 168 } 169 #endif 170 171 static int get_ranges(unsigned char *pst) 172 { 173 unsigned int j; 174 unsigned int speed; 175 u8 fid, vid; 176 177 powernow_table = kzalloc((sizeof(*powernow_table) * 178 (number_scales + 1)), GFP_KERNEL); 179 if (!powernow_table) 180 return -ENOMEM; 181 182 for (j = 0 ; j < number_scales; j++) { 183 fid = *pst++; 184 185 powernow_table[j].frequency = (fsb * fid_codes[fid]) / 10; 186 powernow_table[j].driver_data = fid; /* lower 8 bits */ 187 188 speed = powernow_table[j].frequency; 189 190 if ((fid_codes[fid] % 10) == 5) { 191 #ifdef CONFIG_X86_POWERNOW_K7_ACPI 192 if (have_a0 == 1) 193 invalidate_entry(j); 194 #endif 195 } 196 197 if (speed < minimum_speed) 198 minimum_speed = speed; 199 if (speed > maximum_speed) 200 maximum_speed = speed; 201 202 vid = *pst++; 203 powernow_table[j].driver_data |= (vid << 8); /* upper 8 bits */ 204 205 pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) " 206 "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10, 207 fid_codes[fid] % 10, speed/1000, vid, 208 mobile_vid_table[vid]/1000, 209 mobile_vid_table[vid]%1000); 210 } 211 powernow_table[number_scales].frequency = CPUFREQ_TABLE_END; 212 powernow_table[number_scales].driver_data = 0; 213 214 return 0; 215 } 216 217 218 static void change_FID(int fid) 219 { 220 union msr_fidvidctl fidvidctl; 221 222 rdmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val); 223 if (fidvidctl.bits.FID != fid) { 224 fidvidctl.bits.SGTC = latency; 225 fidvidctl.bits.FID = fid; 226 fidvidctl.bits.VIDC = 0; 227 fidvidctl.bits.FIDC = 1; 228 wrmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val); 229 } 230 } 231 232 233 static void change_VID(int vid) 234 { 235 union msr_fidvidctl fidvidctl; 236 237 rdmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val); 238 if (fidvidctl.bits.VID != vid) { 239 fidvidctl.bits.SGTC = latency; 240 fidvidctl.bits.VID = vid; 241 fidvidctl.bits.FIDC = 0; 242 fidvidctl.bits.VIDC = 1; 243 wrmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val); 244 } 245 } 246 247 248 static int powernow_target(struct cpufreq_policy *policy, unsigned int index) 249 { 250 u8 fid, vid; 251 struct cpufreq_freqs freqs; 252 union msr_fidvidstatus fidvidstatus; 253 int cfid; 254 255 /* fid are the lower 8 bits of the index we stored into 256 * the cpufreq frequency table in powernow_decode_bios, 257 * vid are the upper 8 bits. 258 */ 259 260 fid = powernow_table[index].driver_data & 0xFF; 261 vid = (powernow_table[index].driver_data & 0xFF00) >> 8; 262 263 rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val); 264 cfid = fidvidstatus.bits.CFID; 265 freqs.old = fsb * fid_codes[cfid] / 10; 266 267 freqs.new = powernow_table[index].frequency; 268 269 /* Now do the magic poking into the MSRs. */ 270 271 if (have_a0 == 1) /* A0 errata 5 */ 272 local_irq_disable(); 273 274 if (freqs.old > freqs.new) { 275 /* Going down, so change FID first */ 276 change_FID(fid); 277 change_VID(vid); 278 } else { 279 /* Going up, so change VID first */ 280 change_VID(vid); 281 change_FID(fid); 282 } 283 284 285 if (have_a0 == 1) 286 local_irq_enable(); 287 288 return 0; 289 } 290 291 292 #ifdef CONFIG_X86_POWERNOW_K7_ACPI 293 294 static struct acpi_processor_performance *acpi_processor_perf; 295 296 static int powernow_acpi_init(void) 297 { 298 int i; 299 int retval = 0; 300 union powernow_acpi_control_t pc; 301 302 if (acpi_processor_perf != NULL && powernow_table != NULL) { 303 retval = -EINVAL; 304 goto err0; 305 } 306 307 acpi_processor_perf = kzalloc(sizeof(*acpi_processor_perf), GFP_KERNEL); 308 if (!acpi_processor_perf) { 309 retval = -ENOMEM; 310 goto err0; 311 } 312 313 if (!zalloc_cpumask_var(&acpi_processor_perf->shared_cpu_map, 314 GFP_KERNEL)) { 315 retval = -ENOMEM; 316 goto err05; 317 } 318 319 if (acpi_processor_register_performance(acpi_processor_perf, 0)) { 320 retval = -EIO; 321 goto err1; 322 } 323 324 if (acpi_processor_perf->control_register.space_id != 325 ACPI_ADR_SPACE_FIXED_HARDWARE) { 326 retval = -ENODEV; 327 goto err2; 328 } 329 330 if (acpi_processor_perf->status_register.space_id != 331 ACPI_ADR_SPACE_FIXED_HARDWARE) { 332 retval = -ENODEV; 333 goto err2; 334 } 335 336 number_scales = acpi_processor_perf->state_count; 337 338 if (number_scales < 2) { 339 retval = -ENODEV; 340 goto err2; 341 } 342 343 powernow_table = kzalloc((sizeof(*powernow_table) * 344 (number_scales + 1)), GFP_KERNEL); 345 if (!powernow_table) { 346 retval = -ENOMEM; 347 goto err2; 348 } 349 350 pc.val = (unsigned long) acpi_processor_perf->states[0].control; 351 for (i = 0; i < number_scales; i++) { 352 u8 fid, vid; 353 struct acpi_processor_px *state = 354 &acpi_processor_perf->states[i]; 355 unsigned int speed, speed_mhz; 356 357 pc.val = (unsigned long) state->control; 358 pr_debug("acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n", 359 i, 360 (u32) state->core_frequency, 361 (u32) state->power, 362 (u32) state->transition_latency, 363 (u32) state->control, 364 pc.bits.sgtc); 365 366 vid = pc.bits.vid; 367 fid = pc.bits.fid; 368 369 powernow_table[i].frequency = fsb * fid_codes[fid] / 10; 370 powernow_table[i].driver_data = fid; /* lower 8 bits */ 371 powernow_table[i].driver_data |= (vid << 8); /* upper 8 bits */ 372 373 speed = powernow_table[i].frequency; 374 speed_mhz = speed / 1000; 375 376 /* processor_perflib will multiply the MHz value by 1000 to 377 * get a KHz value (e.g. 1266000). However, powernow-k7 works 378 * with true KHz values (e.g. 1266768). To ensure that all 379 * powernow frequencies are available, we must ensure that 380 * ACPI doesn't restrict them, so we round up the MHz value 381 * to ensure that perflib's computed KHz value is greater than 382 * or equal to powernow's KHz value. 383 */ 384 if (speed % 1000 > 0) 385 speed_mhz++; 386 387 if ((fid_codes[fid] % 10) == 5) { 388 if (have_a0 == 1) 389 invalidate_entry(i); 390 } 391 392 pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) " 393 "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10, 394 fid_codes[fid] % 10, speed_mhz, vid, 395 mobile_vid_table[vid]/1000, 396 mobile_vid_table[vid]%1000); 397 398 if (state->core_frequency != speed_mhz) { 399 state->core_frequency = speed_mhz; 400 pr_debug(" Corrected ACPI frequency to %d\n", 401 speed_mhz); 402 } 403 404 if (latency < pc.bits.sgtc) 405 latency = pc.bits.sgtc; 406 407 if (speed < minimum_speed) 408 minimum_speed = speed; 409 if (speed > maximum_speed) 410 maximum_speed = speed; 411 } 412 413 powernow_table[i].frequency = CPUFREQ_TABLE_END; 414 powernow_table[i].driver_data = 0; 415 416 /* notify BIOS that we exist */ 417 acpi_processor_notify_smm(THIS_MODULE); 418 419 return 0; 420 421 err2: 422 acpi_processor_unregister_performance(0); 423 err1: 424 free_cpumask_var(acpi_processor_perf->shared_cpu_map); 425 err05: 426 kfree(acpi_processor_perf); 427 err0: 428 pr_warn("ACPI perflib can not be used on this platform\n"); 429 acpi_processor_perf = NULL; 430 return retval; 431 } 432 #else 433 static int powernow_acpi_init(void) 434 { 435 pr_info("no support for ACPI processor found - please recompile your kernel with ACPI processor\n"); 436 return -EINVAL; 437 } 438 #endif 439 440 static void print_pst_entry(struct pst_s *pst, unsigned int j) 441 { 442 pr_debug("PST:%d (@%p)\n", j, pst); 443 pr_debug(" cpuid: 0x%x fsb: %d maxFID: 0x%x startvid: 0x%x\n", 444 pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid); 445 } 446 447 static int powernow_decode_bios(int maxfid, int startvid) 448 { 449 struct psb_s *psb; 450 struct pst_s *pst; 451 unsigned int i, j; 452 unsigned char *p; 453 unsigned int etuple; 454 unsigned int ret; 455 456 etuple = cpuid_eax(0x80000001); 457 458 for (i = 0xC0000; i < 0xffff0 ; i += 16) { 459 460 p = phys_to_virt(i); 461 462 if (memcmp(p, "AMDK7PNOW!", 10) == 0) { 463 pr_debug("Found PSB header at %p\n", p); 464 psb = (struct psb_s *) p; 465 pr_debug("Table version: 0x%x\n", psb->tableversion); 466 if (psb->tableversion != 0x12) { 467 pr_info("Sorry, only v1.2 tables supported right now\n"); 468 return -ENODEV; 469 } 470 471 pr_debug("Flags: 0x%x\n", psb->flags); 472 if ((psb->flags & 1) == 0) 473 pr_debug("Mobile voltage regulator\n"); 474 else 475 pr_debug("Desktop voltage regulator\n"); 476 477 latency = psb->settlingtime; 478 if (latency < 100) { 479 pr_info("BIOS set settling time to %d microseconds. Should be at least 100. Correcting.\n", 480 latency); 481 latency = 100; 482 } 483 pr_debug("Settling Time: %d microseconds.\n", 484 psb->settlingtime); 485 pr_debug("Has %d PST tables. (Only dumping ones " 486 "relevant to this CPU).\n", 487 psb->numpst); 488 489 p += sizeof(*psb); 490 491 pst = (struct pst_s *) p; 492 493 for (j = 0; j < psb->numpst; j++) { 494 pst = (struct pst_s *) p; 495 number_scales = pst->numpstates; 496 497 if ((etuple == pst->cpuid) && 498 check_fsb(pst->fsbspeed) && 499 (maxfid == pst->maxfid) && 500 (startvid == pst->startvid)) { 501 print_pst_entry(pst, j); 502 p = (char *)pst + sizeof(*pst); 503 ret = get_ranges(p); 504 return ret; 505 } else { 506 unsigned int k; 507 p = (char *)pst + sizeof(*pst); 508 for (k = 0; k < number_scales; k++) 509 p += 2; 510 } 511 } 512 pr_info("No PST tables match this cpuid (0x%x)\n", 513 etuple); 514 pr_info("This is indicative of a broken BIOS\n"); 515 516 return -EINVAL; 517 } 518 p++; 519 } 520 521 return -ENODEV; 522 } 523 524 525 /* 526 * We use the fact that the bus frequency is somehow 527 * a multiple of 100000/3 khz, then we compute sgtc according 528 * to this multiple. 529 * That way, we match more how AMD thinks all of that work. 530 * We will then get the same kind of behaviour already tested under 531 * the "well-known" other OS. 532 */ 533 static int fixup_sgtc(void) 534 { 535 unsigned int sgtc; 536 unsigned int m; 537 538 m = fsb / 3333; 539 if ((m % 10) >= 5) 540 m += 5; 541 542 m /= 10; 543 544 sgtc = 100 * m * latency; 545 sgtc = sgtc / 3; 546 if (sgtc > 0xfffff) { 547 pr_warn("SGTC too large %d\n", sgtc); 548 sgtc = 0xfffff; 549 } 550 return sgtc; 551 } 552 553 static unsigned int powernow_get(unsigned int cpu) 554 { 555 union msr_fidvidstatus fidvidstatus; 556 unsigned int cfid; 557 558 if (cpu) 559 return 0; 560 rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val); 561 cfid = fidvidstatus.bits.CFID; 562 563 return fsb * fid_codes[cfid] / 10; 564 } 565 566 567 static int acer_cpufreq_pst(const struct dmi_system_id *d) 568 { 569 pr_warn("%s laptop with broken PST tables in BIOS detected\n", 570 d->ident); 571 pr_warn("You need to downgrade to 3A21 (09/09/2002), or try a newer BIOS than 3A71 (01/20/2003)\n"); 572 pr_warn("cpufreq scaling has been disabled as a result of this\n"); 573 return 0; 574 } 575 576 /* 577 * Some Athlon laptops have really fucked PST tables. 578 * A BIOS update is all that can save them. 579 * Mention this, and disable cpufreq. 580 */ 581 static const struct dmi_system_id powernow_dmi_table[] = { 582 { 583 .callback = acer_cpufreq_pst, 584 .ident = "Acer Aspire", 585 .matches = { 586 DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"), 587 DMI_MATCH(DMI_BIOS_VERSION, "3A71"), 588 }, 589 }, 590 { } 591 }; 592 593 static int powernow_cpu_init(struct cpufreq_policy *policy) 594 { 595 union msr_fidvidstatus fidvidstatus; 596 int result; 597 598 if (policy->cpu != 0) 599 return -ENODEV; 600 601 rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val); 602 603 recalibrate_cpu_khz(); 604 605 fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID]; 606 if (!fsb) { 607 pr_warn("can not determine bus frequency\n"); 608 return -EINVAL; 609 } 610 pr_debug("FSB: %3dMHz\n", fsb/1000); 611 612 if (dmi_check_system(powernow_dmi_table) || acpi_force) { 613 pr_info("PSB/PST known to be broken - trying ACPI instead\n"); 614 result = powernow_acpi_init(); 615 } else { 616 result = powernow_decode_bios(fidvidstatus.bits.MFID, 617 fidvidstatus.bits.SVID); 618 if (result) { 619 pr_info("Trying ACPI perflib\n"); 620 maximum_speed = 0; 621 minimum_speed = -1; 622 latency = 0; 623 result = powernow_acpi_init(); 624 if (result) { 625 pr_info("ACPI and legacy methods failed\n"); 626 } 627 } else { 628 /* SGTC use the bus clock as timer */ 629 latency = fixup_sgtc(); 630 pr_info("SGTC: %d\n", latency); 631 } 632 } 633 634 if (result) 635 return result; 636 637 pr_info("Minimum speed %d MHz - Maximum speed %d MHz\n", 638 minimum_speed/1000, maximum_speed/1000); 639 640 policy->cpuinfo.transition_latency = 641 cpufreq_scale(2000000UL, fsb, latency); 642 policy->freq_table = powernow_table; 643 644 return 0; 645 } 646 647 static void powernow_cpu_exit(struct cpufreq_policy *policy) 648 { 649 #ifdef CONFIG_X86_POWERNOW_K7_ACPI 650 if (acpi_processor_perf) { 651 acpi_processor_unregister_performance(0); 652 free_cpumask_var(acpi_processor_perf->shared_cpu_map); 653 kfree(acpi_processor_perf); 654 } 655 #endif 656 657 kfree(powernow_table); 658 } 659 660 static struct cpufreq_driver powernow_driver = { 661 .verify = cpufreq_generic_frequency_table_verify, 662 .target_index = powernow_target, 663 .get = powernow_get, 664 #ifdef CONFIG_X86_POWERNOW_K7_ACPI 665 .bios_limit = acpi_processor_get_bios_limit, 666 #endif 667 .init = powernow_cpu_init, 668 .exit = powernow_cpu_exit, 669 .name = "powernow-k7", 670 .attr = cpufreq_generic_attr, 671 }; 672 673 static int __init powernow_init(void) 674 { 675 if (check_powernow() == 0) 676 return -ENODEV; 677 return cpufreq_register_driver(&powernow_driver); 678 } 679 680 681 static void __exit powernow_exit(void) 682 { 683 cpufreq_unregister_driver(&powernow_driver); 684 } 685 686 module_param(acpi_force, int, 0444); 687 MODULE_PARM_DESC(acpi_force, "Force ACPI to be used."); 688 689 MODULE_AUTHOR("Dave Jones"); 690 MODULE_DESCRIPTION("Powernow driver for AMD K7 processors."); 691 MODULE_LICENSE("GPL"); 692 693 late_initcall(powernow_init); 694 module_exit(powernow_exit); 695 696