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