1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * (C) 2001-2004 Dave Jones. 4 * (C) 2002 Padraig Brady. <padraig@antefacto.com> 5 * 6 * Based upon datasheets & sample CPUs kindly provided by VIA. 7 * 8 * VIA have currently 3 different versions of Longhaul. 9 * Version 1 (Longhaul) uses the BCR2 MSR at 0x1147. 10 * It is present only in Samuel 1 (C5A), Samuel 2 (C5B) stepping 0. 11 * Version 2 of longhaul is backward compatible with v1, but adds 12 * LONGHAUL MSR for purpose of both frequency and voltage scaling. 13 * Present in Samuel 2 (steppings 1-7 only) (C5B), and Ezra (C5C). 14 * Version 3 of longhaul got renamed to Powersaver and redesigned 15 * to use only the POWERSAVER MSR at 0x110a. 16 * It is present in Ezra-T (C5M), Nehemiah (C5X) and above. 17 * It's pretty much the same feature wise to longhaul v2, though 18 * there is provision for scaling FSB too, but this doesn't work 19 * too well in practice so we don't even try to use this. 20 * 21 * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous* 22 */ 23 24 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 25 26 #include <linux/kernel.h> 27 #include <linux/module.h> 28 #include <linux/moduleparam.h> 29 #include <linux/init.h> 30 #include <linux/cpufreq.h> 31 #include <linux/pci.h> 32 #include <linux/slab.h> 33 #include <linux/string.h> 34 #include <linux/delay.h> 35 #include <linux/timex.h> 36 #include <linux/io.h> 37 #include <linux/acpi.h> 38 39 #include <asm/msr.h> 40 #include <asm/cpu_device_id.h> 41 #include <acpi/processor.h> 42 43 #include "longhaul.h" 44 45 #define TYPE_LONGHAUL_V1 1 46 #define TYPE_LONGHAUL_V2 2 47 #define TYPE_POWERSAVER 3 48 49 #define CPU_SAMUEL 1 50 #define CPU_SAMUEL2 2 51 #define CPU_EZRA 3 52 #define CPU_EZRA_T 4 53 #define CPU_NEHEMIAH 5 54 #define CPU_NEHEMIAH_C 6 55 56 /* Flags */ 57 #define USE_ACPI_C3 (1 << 1) 58 #define USE_NORTHBRIDGE (1 << 2) 59 60 static int cpu_model; 61 static unsigned int numscales = 16; 62 static unsigned int fsb; 63 64 static const struct mV_pos *vrm_mV_table; 65 static const unsigned char *mV_vrm_table; 66 67 static unsigned int highest_speed, lowest_speed; /* kHz */ 68 static unsigned int minmult, maxmult; 69 static int can_scale_voltage; 70 static struct acpi_processor *pr; 71 static struct acpi_processor_cx *cx; 72 static u32 acpi_regs_addr; 73 static u8 longhaul_flags; 74 static unsigned int longhaul_index; 75 76 /* Module parameters */ 77 static int scale_voltage; 78 static int disable_acpi_c3; 79 static int revid_errata; 80 static int enable; 81 82 /* Clock ratios multiplied by 10 */ 83 static int mults[32]; 84 static int eblcr[32]; 85 static int longhaul_version; 86 static struct cpufreq_frequency_table *longhaul_table; 87 88 static char speedbuffer[8]; 89 90 static char *print_speed(int speed) 91 { 92 if (speed < 1000) { 93 snprintf(speedbuffer, sizeof(speedbuffer), "%dMHz", speed); 94 return speedbuffer; 95 } 96 97 if (speed%1000 == 0) 98 snprintf(speedbuffer, sizeof(speedbuffer), 99 "%dGHz", speed/1000); 100 else 101 snprintf(speedbuffer, sizeof(speedbuffer), 102 "%d.%dGHz", speed/1000, (speed%1000)/100); 103 104 return speedbuffer; 105 } 106 107 108 static unsigned int calc_speed(int mult) 109 { 110 int khz; 111 khz = (mult/10)*fsb; 112 if (mult%10) 113 khz += fsb/2; 114 khz *= 1000; 115 return khz; 116 } 117 118 119 static int longhaul_get_cpu_mult(void) 120 { 121 unsigned long invalue = 0, lo, hi; 122 123 rdmsr(MSR_IA32_EBL_CR_POWERON, lo, hi); 124 invalue = (lo & (1<<22|1<<23|1<<24|1<<25))>>22; 125 if (longhaul_version == TYPE_LONGHAUL_V2 || 126 longhaul_version == TYPE_POWERSAVER) { 127 if (lo & (1<<27)) 128 invalue += 16; 129 } 130 return eblcr[invalue]; 131 } 132 133 /* For processor with BCR2 MSR */ 134 135 static void do_longhaul1(unsigned int mults_index) 136 { 137 union msr_bcr2 bcr2; 138 139 rdmsrl(MSR_VIA_BCR2, bcr2.val); 140 /* Enable software clock multiplier */ 141 bcr2.bits.ESOFTBF = 1; 142 bcr2.bits.CLOCKMUL = mults_index & 0xff; 143 144 /* Sync to timer tick */ 145 safe_halt(); 146 /* Change frequency on next halt or sleep */ 147 wrmsrl(MSR_VIA_BCR2, bcr2.val); 148 /* Invoke transition */ 149 ACPI_FLUSH_CPU_CACHE(); 150 halt(); 151 152 /* Disable software clock multiplier */ 153 local_irq_disable(); 154 rdmsrl(MSR_VIA_BCR2, bcr2.val); 155 bcr2.bits.ESOFTBF = 0; 156 wrmsrl(MSR_VIA_BCR2, bcr2.val); 157 } 158 159 /* For processor with Longhaul MSR */ 160 161 static void do_powersaver(int cx_address, unsigned int mults_index, 162 unsigned int dir) 163 { 164 union msr_longhaul longhaul; 165 u32 t; 166 167 rdmsrl(MSR_VIA_LONGHAUL, longhaul.val); 168 /* Setup new frequency */ 169 if (!revid_errata) 170 longhaul.bits.RevisionKey = longhaul.bits.RevisionID; 171 else 172 longhaul.bits.RevisionKey = 0; 173 longhaul.bits.SoftBusRatio = mults_index & 0xf; 174 longhaul.bits.SoftBusRatio4 = (mults_index & 0x10) >> 4; 175 /* Setup new voltage */ 176 if (can_scale_voltage) 177 longhaul.bits.SoftVID = (mults_index >> 8) & 0x1f; 178 /* Sync to timer tick */ 179 safe_halt(); 180 /* Raise voltage if necessary */ 181 if (can_scale_voltage && dir) { 182 longhaul.bits.EnableSoftVID = 1; 183 wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); 184 /* Change voltage */ 185 if (!cx_address) { 186 ACPI_FLUSH_CPU_CACHE(); 187 halt(); 188 } else { 189 ACPI_FLUSH_CPU_CACHE(); 190 /* Invoke C3 */ 191 inb(cx_address); 192 /* Dummy op - must do something useless after P_LVL3 193 * read */ 194 t = inl(acpi_gbl_FADT.xpm_timer_block.address); 195 } 196 longhaul.bits.EnableSoftVID = 0; 197 wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); 198 } 199 200 /* Change frequency on next halt or sleep */ 201 longhaul.bits.EnableSoftBusRatio = 1; 202 wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); 203 if (!cx_address) { 204 ACPI_FLUSH_CPU_CACHE(); 205 halt(); 206 } else { 207 ACPI_FLUSH_CPU_CACHE(); 208 /* Invoke C3 */ 209 inb(cx_address); 210 /* Dummy op - must do something useless after P_LVL3 read */ 211 t = inl(acpi_gbl_FADT.xpm_timer_block.address); 212 } 213 /* Disable bus ratio bit */ 214 longhaul.bits.EnableSoftBusRatio = 0; 215 wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); 216 217 /* Reduce voltage if necessary */ 218 if (can_scale_voltage && !dir) { 219 longhaul.bits.EnableSoftVID = 1; 220 wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); 221 /* Change voltage */ 222 if (!cx_address) { 223 ACPI_FLUSH_CPU_CACHE(); 224 halt(); 225 } else { 226 ACPI_FLUSH_CPU_CACHE(); 227 /* Invoke C3 */ 228 inb(cx_address); 229 /* Dummy op - must do something useless after P_LVL3 230 * read */ 231 t = inl(acpi_gbl_FADT.xpm_timer_block.address); 232 } 233 longhaul.bits.EnableSoftVID = 0; 234 wrmsrl(MSR_VIA_LONGHAUL, longhaul.val); 235 } 236 } 237 238 /** 239 * longhaul_setstate() 240 * @policy: cpufreq_policy structure containing the current policy. 241 * @table_index: index of the frequency within the cpufreq_frequency_table. 242 * 243 * Sets a new clock ratio. 244 */ 245 246 static int longhaul_setstate(struct cpufreq_policy *policy, 247 unsigned int table_index) 248 { 249 unsigned int mults_index; 250 int speed, mult; 251 struct cpufreq_freqs freqs; 252 unsigned long flags; 253 unsigned int pic1_mask, pic2_mask; 254 u16 bm_status = 0; 255 u32 bm_timeout = 1000; 256 unsigned int dir = 0; 257 258 mults_index = longhaul_table[table_index].driver_data; 259 /* Safety precautions */ 260 mult = mults[mults_index & 0x1f]; 261 if (mult == -1) 262 return -EINVAL; 263 264 speed = calc_speed(mult); 265 if ((speed > highest_speed) || (speed < lowest_speed)) 266 return -EINVAL; 267 268 /* Voltage transition before frequency transition? */ 269 if (can_scale_voltage && longhaul_index < table_index) 270 dir = 1; 271 272 freqs.old = calc_speed(longhaul_get_cpu_mult()); 273 freqs.new = speed; 274 275 pr_debug("Setting to FSB:%dMHz Mult:%d.%dx (%s)\n", 276 fsb, mult/10, mult%10, print_speed(speed/1000)); 277 retry_loop: 278 preempt_disable(); 279 local_irq_save(flags); 280 281 pic2_mask = inb(0xA1); 282 pic1_mask = inb(0x21); /* works on C3. save mask. */ 283 outb(0xFF, 0xA1); /* Overkill */ 284 outb(0xFE, 0x21); /* TMR0 only */ 285 286 /* Wait while PCI bus is busy. */ 287 if (acpi_regs_addr && (longhaul_flags & USE_NORTHBRIDGE 288 || ((pr != NULL) && pr->flags.bm_control))) { 289 bm_status = inw(acpi_regs_addr); 290 bm_status &= 1 << 4; 291 while (bm_status && bm_timeout) { 292 outw(1 << 4, acpi_regs_addr); 293 bm_timeout--; 294 bm_status = inw(acpi_regs_addr); 295 bm_status &= 1 << 4; 296 } 297 } 298 299 if (longhaul_flags & USE_NORTHBRIDGE) { 300 /* Disable AGP and PCI arbiters */ 301 outb(3, 0x22); 302 } else if ((pr != NULL) && pr->flags.bm_control) { 303 /* Disable bus master arbitration */ 304 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1); 305 } 306 switch (longhaul_version) { 307 308 /* 309 * Longhaul v1. (Samuel[C5A] and Samuel2 stepping 0[C5B]) 310 * Software controlled multipliers only. 311 */ 312 case TYPE_LONGHAUL_V1: 313 do_longhaul1(mults_index); 314 break; 315 316 /* 317 * Longhaul v2 appears in Samuel2 Steppings 1->7 [C5B] and Ezra [C5C] 318 * 319 * Longhaul v3 (aka Powersaver). (Ezra-T [C5M] & Nehemiah [C5N]) 320 * Nehemiah can do FSB scaling too, but this has never been proven 321 * to work in practice. 322 */ 323 case TYPE_LONGHAUL_V2: 324 case TYPE_POWERSAVER: 325 if (longhaul_flags & USE_ACPI_C3) { 326 /* Don't allow wakeup */ 327 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 0); 328 do_powersaver(cx->address, mults_index, dir); 329 } else { 330 do_powersaver(0, mults_index, dir); 331 } 332 break; 333 } 334 335 if (longhaul_flags & USE_NORTHBRIDGE) { 336 /* Enable arbiters */ 337 outb(0, 0x22); 338 } else if ((pr != NULL) && pr->flags.bm_control) { 339 /* Enable bus master arbitration */ 340 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0); 341 } 342 outb(pic2_mask, 0xA1); /* restore mask */ 343 outb(pic1_mask, 0x21); 344 345 local_irq_restore(flags); 346 preempt_enable(); 347 348 freqs.new = calc_speed(longhaul_get_cpu_mult()); 349 /* Check if requested frequency is set. */ 350 if (unlikely(freqs.new != speed)) { 351 pr_info("Failed to set requested frequency!\n"); 352 /* Revision ID = 1 but processor is expecting revision key 353 * equal to 0. Jumpers at the bottom of processor will change 354 * multiplier and FSB, but will not change bits in Longhaul 355 * MSR nor enable voltage scaling. */ 356 if (!revid_errata) { 357 pr_info("Enabling \"Ignore Revision ID\" option\n"); 358 revid_errata = 1; 359 msleep(200); 360 goto retry_loop; 361 } 362 /* Why ACPI C3 sometimes doesn't work is a mystery for me. 363 * But it does happen. Processor is entering ACPI C3 state, 364 * but it doesn't change frequency. I tried poking various 365 * bits in northbridge registers, but without success. */ 366 if (longhaul_flags & USE_ACPI_C3) { 367 pr_info("Disabling ACPI C3 support\n"); 368 longhaul_flags &= ~USE_ACPI_C3; 369 if (revid_errata) { 370 pr_info("Disabling \"Ignore Revision ID\" option\n"); 371 revid_errata = 0; 372 } 373 msleep(200); 374 goto retry_loop; 375 } 376 /* This shouldn't happen. Longhaul ver. 2 was reported not 377 * working on processors without voltage scaling, but with 378 * RevID = 1. RevID errata will make things right. Just 379 * to be 100% sure. */ 380 if (longhaul_version == TYPE_LONGHAUL_V2) { 381 pr_info("Switching to Longhaul ver. 1\n"); 382 longhaul_version = TYPE_LONGHAUL_V1; 383 msleep(200); 384 goto retry_loop; 385 } 386 } 387 388 if (!bm_timeout) { 389 pr_info("Warning: Timeout while waiting for idle PCI bus\n"); 390 return -EBUSY; 391 } 392 393 return 0; 394 } 395 396 /* 397 * Centaur decided to make life a little more tricky. 398 * Only longhaul v1 is allowed to read EBLCR BSEL[0:1]. 399 * Samuel2 and above have to try and guess what the FSB is. 400 * We do this by assuming we booted at maximum multiplier, and interpolate 401 * between that value multiplied by possible FSBs and cpu_mhz which 402 * was calculated at boot time. Really ugly, but no other way to do this. 403 */ 404 405 #define ROUNDING 0xf 406 407 static int guess_fsb(int mult) 408 { 409 int speed = cpu_khz / 1000; 410 int i; 411 static const int speeds[] = { 666, 1000, 1333, 2000 }; 412 int f_max, f_min; 413 414 for (i = 0; i < ARRAY_SIZE(speeds); i++) { 415 f_max = ((speeds[i] * mult) + 50) / 100; 416 f_max += (ROUNDING / 2); 417 f_min = f_max - ROUNDING; 418 if ((speed <= f_max) && (speed >= f_min)) 419 return speeds[i] / 10; 420 } 421 return 0; 422 } 423 424 425 static int longhaul_get_ranges(void) 426 { 427 unsigned int i, j, k = 0; 428 unsigned int ratio; 429 int mult; 430 431 /* Get current frequency */ 432 mult = longhaul_get_cpu_mult(); 433 if (mult == -1) { 434 pr_info("Invalid (reserved) multiplier!\n"); 435 return -EINVAL; 436 } 437 fsb = guess_fsb(mult); 438 if (fsb == 0) { 439 pr_info("Invalid (reserved) FSB!\n"); 440 return -EINVAL; 441 } 442 /* Get max multiplier - as we always did. 443 * Longhaul MSR is useful only when voltage scaling is enabled. 444 * C3 is booting at max anyway. */ 445 maxmult = mult; 446 /* Get min multiplier */ 447 switch (cpu_model) { 448 case CPU_NEHEMIAH: 449 minmult = 50; 450 break; 451 case CPU_NEHEMIAH_C: 452 minmult = 40; 453 break; 454 default: 455 minmult = 30; 456 break; 457 } 458 459 pr_debug("MinMult:%d.%dx MaxMult:%d.%dx\n", 460 minmult/10, minmult%10, maxmult/10, maxmult%10); 461 462 highest_speed = calc_speed(maxmult); 463 lowest_speed = calc_speed(minmult); 464 pr_debug("FSB:%dMHz Lowest speed: %s Highest speed:%s\n", fsb, 465 print_speed(lowest_speed/1000), 466 print_speed(highest_speed/1000)); 467 468 if (lowest_speed == highest_speed) { 469 pr_info("highestspeed == lowest, aborting\n"); 470 return -EINVAL; 471 } 472 if (lowest_speed > highest_speed) { 473 pr_info("nonsense! lowest (%d > %d) !\n", 474 lowest_speed, highest_speed); 475 return -EINVAL; 476 } 477 478 longhaul_table = kcalloc(numscales + 1, sizeof(*longhaul_table), 479 GFP_KERNEL); 480 if (!longhaul_table) 481 return -ENOMEM; 482 483 for (j = 0; j < numscales; j++) { 484 ratio = mults[j]; 485 if (ratio == -1) 486 continue; 487 if (ratio > maxmult || ratio < minmult) 488 continue; 489 longhaul_table[k].frequency = calc_speed(ratio); 490 longhaul_table[k].driver_data = j; 491 k++; 492 } 493 if (k <= 1) { 494 kfree(longhaul_table); 495 return -ENODEV; 496 } 497 /* Sort */ 498 for (j = 0; j < k - 1; j++) { 499 unsigned int min_f, min_i; 500 min_f = longhaul_table[j].frequency; 501 min_i = j; 502 for (i = j + 1; i < k; i++) { 503 if (longhaul_table[i].frequency < min_f) { 504 min_f = longhaul_table[i].frequency; 505 min_i = i; 506 } 507 } 508 if (min_i != j) { 509 swap(longhaul_table[j].frequency, 510 longhaul_table[min_i].frequency); 511 swap(longhaul_table[j].driver_data, 512 longhaul_table[min_i].driver_data); 513 } 514 } 515 516 longhaul_table[k].frequency = CPUFREQ_TABLE_END; 517 518 /* Find index we are running on */ 519 for (j = 0; j < k; j++) { 520 if (mults[longhaul_table[j].driver_data & 0x1f] == mult) { 521 longhaul_index = j; 522 break; 523 } 524 } 525 return 0; 526 } 527 528 529 static void longhaul_setup_voltagescaling(void) 530 { 531 struct cpufreq_frequency_table *freq_pos; 532 union msr_longhaul longhaul; 533 struct mV_pos minvid, maxvid, vid; 534 unsigned int j, speed, pos, kHz_step, numvscales; 535 int min_vid_speed; 536 537 rdmsrl(MSR_VIA_LONGHAUL, longhaul.val); 538 if (!(longhaul.bits.RevisionID & 1)) { 539 pr_info("Voltage scaling not supported by CPU\n"); 540 return; 541 } 542 543 if (!longhaul.bits.VRMRev) { 544 pr_info("VRM 8.5\n"); 545 vrm_mV_table = &vrm85_mV[0]; 546 mV_vrm_table = &mV_vrm85[0]; 547 } else { 548 pr_info("Mobile VRM\n"); 549 if (cpu_model < CPU_NEHEMIAH) 550 return; 551 vrm_mV_table = &mobilevrm_mV[0]; 552 mV_vrm_table = &mV_mobilevrm[0]; 553 } 554 555 minvid = vrm_mV_table[longhaul.bits.MinimumVID]; 556 maxvid = vrm_mV_table[longhaul.bits.MaximumVID]; 557 558 if (minvid.mV == 0 || maxvid.mV == 0 || minvid.mV > maxvid.mV) { 559 pr_info("Bogus values Min:%d.%03d Max:%d.%03d - Voltage scaling disabled\n", 560 minvid.mV/1000, minvid.mV%1000, 561 maxvid.mV/1000, maxvid.mV%1000); 562 return; 563 } 564 565 if (minvid.mV == maxvid.mV) { 566 pr_info("Claims to support voltage scaling but min & max are both %d.%03d - Voltage scaling disabled\n", 567 maxvid.mV/1000, maxvid.mV%1000); 568 return; 569 } 570 571 /* How many voltage steps*/ 572 numvscales = maxvid.pos - minvid.pos + 1; 573 pr_info("Max VID=%d.%03d Min VID=%d.%03d, %d possible voltage scales\n", 574 maxvid.mV/1000, maxvid.mV%1000, 575 minvid.mV/1000, minvid.mV%1000, 576 numvscales); 577 578 /* Calculate max frequency at min voltage */ 579 j = longhaul.bits.MinMHzBR; 580 if (longhaul.bits.MinMHzBR4) 581 j += 16; 582 min_vid_speed = eblcr[j]; 583 if (min_vid_speed == -1) 584 return; 585 switch (longhaul.bits.MinMHzFSB) { 586 case 0: 587 min_vid_speed *= 13333; 588 break; 589 case 1: 590 min_vid_speed *= 10000; 591 break; 592 case 3: 593 min_vid_speed *= 6666; 594 break; 595 default: 596 return; 597 } 598 if (min_vid_speed >= highest_speed) 599 return; 600 /* Calculate kHz for one voltage step */ 601 kHz_step = (highest_speed - min_vid_speed) / numvscales; 602 603 cpufreq_for_each_entry_idx(freq_pos, longhaul_table, j) { 604 speed = freq_pos->frequency; 605 if (speed > min_vid_speed) 606 pos = (speed - min_vid_speed) / kHz_step + minvid.pos; 607 else 608 pos = minvid.pos; 609 freq_pos->driver_data |= mV_vrm_table[pos] << 8; 610 vid = vrm_mV_table[mV_vrm_table[pos]]; 611 pr_info("f: %d kHz, index: %d, vid: %d mV\n", 612 speed, j, vid.mV); 613 } 614 615 can_scale_voltage = 1; 616 pr_info("Voltage scaling enabled\n"); 617 } 618 619 620 static int longhaul_target(struct cpufreq_policy *policy, 621 unsigned int table_index) 622 { 623 unsigned int i; 624 unsigned int dir = 0; 625 u8 vid, current_vid; 626 int retval = 0; 627 628 if (!can_scale_voltage) 629 retval = longhaul_setstate(policy, table_index); 630 else { 631 /* On test system voltage transitions exceeding single 632 * step up or down were turning motherboard off. Both 633 * "ondemand" and "userspace" are unsafe. C7 is doing 634 * this in hardware, C3 is old and we need to do this 635 * in software. */ 636 i = longhaul_index; 637 current_vid = (longhaul_table[longhaul_index].driver_data >> 8); 638 current_vid &= 0x1f; 639 if (table_index > longhaul_index) 640 dir = 1; 641 while (i != table_index) { 642 vid = (longhaul_table[i].driver_data >> 8) & 0x1f; 643 if (vid != current_vid) { 644 retval = longhaul_setstate(policy, i); 645 current_vid = vid; 646 msleep(200); 647 } 648 if (dir) 649 i++; 650 else 651 i--; 652 } 653 retval = longhaul_setstate(policy, table_index); 654 } 655 656 longhaul_index = table_index; 657 return retval; 658 } 659 660 661 static unsigned int longhaul_get(unsigned int cpu) 662 { 663 if (cpu) 664 return 0; 665 return calc_speed(longhaul_get_cpu_mult()); 666 } 667 668 static acpi_status longhaul_walk_callback(acpi_handle obj_handle, 669 u32 nesting_level, 670 void *context, void **return_value) 671 { 672 struct acpi_device *d = acpi_fetch_acpi_dev(obj_handle); 673 674 if (!d) 675 return 0; 676 677 *return_value = acpi_driver_data(d); 678 return 1; 679 } 680 681 /* VIA don't support PM2 reg, but have something similar */ 682 static int enable_arbiter_disable(void) 683 { 684 struct pci_dev *dev; 685 int status = 1; 686 int reg; 687 u8 pci_cmd; 688 689 /* Find PLE133 host bridge */ 690 reg = 0x78; 691 dev = pci_get_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8601_0, 692 NULL); 693 /* Find PM133/VT8605 host bridge */ 694 if (dev == NULL) 695 dev = pci_get_device(PCI_VENDOR_ID_VIA, 696 PCI_DEVICE_ID_VIA_8605_0, NULL); 697 /* Find CLE266 host bridge */ 698 if (dev == NULL) { 699 reg = 0x76; 700 dev = pci_get_device(PCI_VENDOR_ID_VIA, 701 PCI_DEVICE_ID_VIA_862X_0, NULL); 702 /* Find CN400 V-Link host bridge */ 703 if (dev == NULL) 704 dev = pci_get_device(PCI_VENDOR_ID_VIA, 0x7259, NULL); 705 } 706 if (dev != NULL) { 707 /* Enable access to port 0x22 */ 708 pci_read_config_byte(dev, reg, &pci_cmd); 709 if (!(pci_cmd & 1<<7)) { 710 pci_cmd |= 1<<7; 711 pci_write_config_byte(dev, reg, pci_cmd); 712 pci_read_config_byte(dev, reg, &pci_cmd); 713 if (!(pci_cmd & 1<<7)) { 714 pr_err("Can't enable access to port 0x22\n"); 715 status = 0; 716 } 717 } 718 pci_dev_put(dev); 719 return status; 720 } 721 return 0; 722 } 723 724 static int longhaul_setup_southbridge(void) 725 { 726 struct pci_dev *dev; 727 u8 pci_cmd; 728 729 /* Find VT8235 southbridge */ 730 dev = pci_get_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235, NULL); 731 if (dev == NULL) 732 /* Find VT8237 southbridge */ 733 dev = pci_get_device(PCI_VENDOR_ID_VIA, 734 PCI_DEVICE_ID_VIA_8237, NULL); 735 if (dev != NULL) { 736 /* Set transition time to max */ 737 pci_read_config_byte(dev, 0xec, &pci_cmd); 738 pci_cmd &= ~(1 << 2); 739 pci_write_config_byte(dev, 0xec, pci_cmd); 740 pci_read_config_byte(dev, 0xe4, &pci_cmd); 741 pci_cmd &= ~(1 << 7); 742 pci_write_config_byte(dev, 0xe4, pci_cmd); 743 pci_read_config_byte(dev, 0xe5, &pci_cmd); 744 pci_cmd |= 1 << 7; 745 pci_write_config_byte(dev, 0xe5, pci_cmd); 746 /* Get address of ACPI registers block*/ 747 pci_read_config_byte(dev, 0x81, &pci_cmd); 748 if (pci_cmd & 1 << 7) { 749 pci_read_config_dword(dev, 0x88, &acpi_regs_addr); 750 acpi_regs_addr &= 0xff00; 751 pr_info("ACPI I/O at 0x%x\n", acpi_regs_addr); 752 } 753 754 pci_dev_put(dev); 755 return 1; 756 } 757 return 0; 758 } 759 760 static int longhaul_cpu_init(struct cpufreq_policy *policy) 761 { 762 struct cpuinfo_x86 *c = &cpu_data(0); 763 char *cpuname = NULL; 764 int ret; 765 u32 lo, hi; 766 767 /* Check what we have on this motherboard */ 768 switch (c->x86_model) { 769 case 6: 770 cpu_model = CPU_SAMUEL; 771 cpuname = "C3 'Samuel' [C5A]"; 772 longhaul_version = TYPE_LONGHAUL_V1; 773 memcpy(mults, samuel1_mults, sizeof(samuel1_mults)); 774 memcpy(eblcr, samuel1_eblcr, sizeof(samuel1_eblcr)); 775 break; 776 777 case 7: 778 switch (c->x86_stepping) { 779 case 0: 780 longhaul_version = TYPE_LONGHAUL_V1; 781 cpu_model = CPU_SAMUEL2; 782 cpuname = "C3 'Samuel 2' [C5B]"; 783 /* Note, this is not a typo, early Samuel2's had 784 * Samuel1 ratios. */ 785 memcpy(mults, samuel1_mults, sizeof(samuel1_mults)); 786 memcpy(eblcr, samuel2_eblcr, sizeof(samuel2_eblcr)); 787 break; 788 case 1 ... 15: 789 longhaul_version = TYPE_LONGHAUL_V2; 790 if (c->x86_stepping < 8) { 791 cpu_model = CPU_SAMUEL2; 792 cpuname = "C3 'Samuel 2' [C5B]"; 793 } else { 794 cpu_model = CPU_EZRA; 795 cpuname = "C3 'Ezra' [C5C]"; 796 } 797 memcpy(mults, ezra_mults, sizeof(ezra_mults)); 798 memcpy(eblcr, ezra_eblcr, sizeof(ezra_eblcr)); 799 break; 800 } 801 break; 802 803 case 8: 804 cpu_model = CPU_EZRA_T; 805 cpuname = "C3 'Ezra-T' [C5M]"; 806 longhaul_version = TYPE_POWERSAVER; 807 numscales = 32; 808 memcpy(mults, ezrat_mults, sizeof(ezrat_mults)); 809 memcpy(eblcr, ezrat_eblcr, sizeof(ezrat_eblcr)); 810 break; 811 812 case 9: 813 longhaul_version = TYPE_POWERSAVER; 814 numscales = 32; 815 memcpy(mults, nehemiah_mults, sizeof(nehemiah_mults)); 816 memcpy(eblcr, nehemiah_eblcr, sizeof(nehemiah_eblcr)); 817 switch (c->x86_stepping) { 818 case 0 ... 1: 819 cpu_model = CPU_NEHEMIAH; 820 cpuname = "C3 'Nehemiah A' [C5XLOE]"; 821 break; 822 case 2 ... 4: 823 cpu_model = CPU_NEHEMIAH; 824 cpuname = "C3 'Nehemiah B' [C5XLOH]"; 825 break; 826 case 5 ... 15: 827 cpu_model = CPU_NEHEMIAH_C; 828 cpuname = "C3 'Nehemiah C' [C5P]"; 829 break; 830 } 831 break; 832 833 default: 834 cpuname = "Unknown"; 835 break; 836 } 837 /* Check Longhaul ver. 2 */ 838 if (longhaul_version == TYPE_LONGHAUL_V2) { 839 rdmsr(MSR_VIA_LONGHAUL, lo, hi); 840 if (lo == 0 && hi == 0) 841 /* Looks like MSR isn't present */ 842 longhaul_version = TYPE_LONGHAUL_V1; 843 } 844 845 pr_info("VIA %s CPU detected. ", cpuname); 846 switch (longhaul_version) { 847 case TYPE_LONGHAUL_V1: 848 case TYPE_LONGHAUL_V2: 849 pr_cont("Longhaul v%d supported\n", longhaul_version); 850 break; 851 case TYPE_POWERSAVER: 852 pr_cont("Powersaver supported\n"); 853 break; 854 } 855 856 /* Doesn't hurt */ 857 longhaul_setup_southbridge(); 858 859 /* Find ACPI data for processor */ 860 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT, 861 ACPI_UINT32_MAX, &longhaul_walk_callback, NULL, 862 NULL, (void *)&pr); 863 864 /* Check ACPI support for C3 state */ 865 if (pr != NULL && longhaul_version == TYPE_POWERSAVER) { 866 cx = &pr->power.states[ACPI_STATE_C3]; 867 if (cx->address > 0 && cx->latency <= 1000) 868 longhaul_flags |= USE_ACPI_C3; 869 } 870 /* Disable if it isn't working */ 871 if (disable_acpi_c3) 872 longhaul_flags &= ~USE_ACPI_C3; 873 /* Check if northbridge is friendly */ 874 if (enable_arbiter_disable()) 875 longhaul_flags |= USE_NORTHBRIDGE; 876 877 /* Check ACPI support for bus master arbiter disable */ 878 if (!(longhaul_flags & USE_ACPI_C3 879 || longhaul_flags & USE_NORTHBRIDGE) 880 && ((pr == NULL) || !(pr->flags.bm_control))) { 881 pr_err("No ACPI support: Unsupported northbridge\n"); 882 return -ENODEV; 883 } 884 885 if (longhaul_flags & USE_NORTHBRIDGE) 886 pr_info("Using northbridge support\n"); 887 if (longhaul_flags & USE_ACPI_C3) 888 pr_info("Using ACPI support\n"); 889 890 ret = longhaul_get_ranges(); 891 if (ret != 0) 892 return ret; 893 894 if ((longhaul_version != TYPE_LONGHAUL_V1) && (scale_voltage != 0)) 895 longhaul_setup_voltagescaling(); 896 897 policy->transition_delay_us = 200000; /* usec */ 898 policy->freq_table = longhaul_table; 899 900 return 0; 901 } 902 903 static struct cpufreq_driver longhaul_driver = { 904 .verify = cpufreq_generic_frequency_table_verify, 905 .target_index = longhaul_target, 906 .get = longhaul_get, 907 .init = longhaul_cpu_init, 908 .name = "longhaul", 909 .attr = cpufreq_generic_attr, 910 }; 911 912 static const struct x86_cpu_id longhaul_id[] = { 913 X86_MATCH_VENDOR_FAM(CENTAUR, 6, NULL), 914 {} 915 }; 916 MODULE_DEVICE_TABLE(x86cpu, longhaul_id); 917 918 static int __init longhaul_init(void) 919 { 920 struct cpuinfo_x86 *c = &cpu_data(0); 921 922 if (!x86_match_cpu(longhaul_id)) 923 return -ENODEV; 924 925 if (!enable) { 926 pr_err("Option \"enable\" not set - Aborting\n"); 927 return -ENODEV; 928 } 929 #ifdef CONFIG_SMP 930 if (num_online_cpus() > 1) { 931 pr_err("More than 1 CPU detected, longhaul disabled\n"); 932 return -ENODEV; 933 } 934 #endif 935 #ifdef CONFIG_X86_IO_APIC 936 if (boot_cpu_has(X86_FEATURE_APIC)) { 937 pr_err("APIC detected. Longhaul is currently broken in this configuration.\n"); 938 return -ENODEV; 939 } 940 #endif 941 switch (c->x86_model) { 942 case 6 ... 9: 943 return cpufreq_register_driver(&longhaul_driver); 944 case 10: 945 pr_err("Use acpi-cpufreq driver for VIA C7\n"); 946 } 947 948 return -ENODEV; 949 } 950 951 952 static void __exit longhaul_exit(void) 953 { 954 struct cpufreq_policy *policy = cpufreq_cpu_get(0); 955 int i; 956 957 for (i = 0; i < numscales; i++) { 958 if (mults[i] == maxmult) { 959 struct cpufreq_freqs freqs; 960 961 freqs.old = policy->cur; 962 freqs.new = longhaul_table[i].frequency; 963 freqs.flags = 0; 964 965 cpufreq_freq_transition_begin(policy, &freqs); 966 longhaul_setstate(policy, i); 967 cpufreq_freq_transition_end(policy, &freqs, 0); 968 break; 969 } 970 } 971 972 cpufreq_cpu_put(policy); 973 cpufreq_unregister_driver(&longhaul_driver); 974 kfree(longhaul_table); 975 } 976 977 /* Even if BIOS is exporting ACPI C3 state, and it is used 978 * with success when CPU is idle, this state doesn't 979 * trigger frequency transition in some cases. */ 980 module_param(disable_acpi_c3, int, 0644); 981 MODULE_PARM_DESC(disable_acpi_c3, "Don't use ACPI C3 support"); 982 /* Change CPU voltage with frequency. Very useful to save 983 * power, but most VIA C3 processors aren't supporting it. */ 984 module_param(scale_voltage, int, 0644); 985 MODULE_PARM_DESC(scale_voltage, "Scale voltage of processor"); 986 /* Force revision key to 0 for processors which doesn't 987 * support voltage scaling, but are introducing itself as 988 * such. */ 989 module_param(revid_errata, int, 0644); 990 MODULE_PARM_DESC(revid_errata, "Ignore CPU Revision ID"); 991 /* By default driver is disabled to prevent incompatible 992 * system freeze. */ 993 module_param(enable, int, 0644); 994 MODULE_PARM_DESC(enable, "Enable driver"); 995 996 MODULE_AUTHOR("Dave Jones"); 997 MODULE_DESCRIPTION("Longhaul driver for VIA Cyrix processors."); 998 MODULE_LICENSE("GPL"); 999 1000 late_initcall(longhaul_init); 1001 module_exit(longhaul_exit); 1002