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
60static int cpu_model;
61static unsigned int numscales = 16;
62static unsigned int fsb;
63
64static const struct mV_pos *vrm_mV_table;
65static const unsigned char *mV_vrm_table;
66
67static unsigned int highest_speed, lowest_speed; /* kHz */
68static unsigned int minmult, maxmult;
69static int can_scale_voltage;
70static struct acpi_processor *pr;
71static struct acpi_processor_cx *cx;
72static u32 acpi_regs_addr;
73static u8 longhaul_flags;
74static unsigned int longhaul_index;
75
76/* Module parameters */
77static int scale_voltage;
78static int disable_acpi_c3;
79static int revid_errata;
80static int enable;
81
82/* Clock ratios multiplied by 10 */
83static int mults[32];
84static int eblcr[32];
85static int longhaul_version;
86static struct cpufreq_frequency_table *longhaul_table;
87
88static char speedbuffer[8];
89
90static char *print_speed(int speed)
91{
92 if (speed < 1000) {
93 snprintf(buf: speedbuffer, size: sizeof(speedbuffer), fmt: "%dMHz", speed);
94 return speedbuffer;
95 }
96
97 if (speed%1000 == 0)
98 snprintf(buf: speedbuffer, size: sizeof(speedbuffer),
99 fmt: "%dGHz", speed/1000);
100 else
101 snprintf(buf: speedbuffer, size: sizeof(speedbuffer),
102 fmt: "%d.%dGHz", speed/1000, (speed%1000)/100);
103
104 return speedbuffer;
105}
106
107
108static 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
119static 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
135static 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, val: 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, val: bcr2.val);
157}
158
159/* For processor with Longhaul MSR */
160
161static 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, val: 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(port: cx_address);
192 /* Dummy op - must do something useless after P_LVL3
193 * read */
194 t = inl(port: acpi_gbl_FADT.xpm_timer_block.address);
195 }
196 longhaul.bits.EnableSoftVID = 0;
197 wrmsrl(MSR_VIA_LONGHAUL, val: longhaul.val);
198 }
199
200 /* Change frequency on next halt or sleep */
201 longhaul.bits.EnableSoftBusRatio = 1;
202 wrmsrl(MSR_VIA_LONGHAUL, val: 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(port: cx_address);
210 /* Dummy op - must do something useless after P_LVL3 read */
211 t = inl(port: acpi_gbl_FADT.xpm_timer_block.address);
212 }
213 /* Disable bus ratio bit */
214 longhaul.bits.EnableSoftBusRatio = 0;
215 wrmsrl(MSR_VIA_LONGHAUL, val: longhaul.val);
216
217 /* Reduce voltage if necessary */
218 if (can_scale_voltage && !dir) {
219 longhaul.bits.EnableSoftVID = 1;
220 wrmsrl(MSR_VIA_LONGHAUL, val: 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(port: cx_address);
229 /* Dummy op - must do something useless after P_LVL3
230 * read */
231 t = inl(port: acpi_gbl_FADT.xpm_timer_block.address);
232 }
233 longhaul.bits.EnableSoftVID = 0;
234 wrmsrl(MSR_VIA_LONGHAUL, val: 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
245static 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(mult: 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));
276retry_loop:
277 preempt_disable();
278 local_irq_save(flags);
279
280 pic2_mask = inb(port: 0xA1);
281 pic1_mask = inb(port: 0x21); /* works on C3. save mask. */
282 outb(value: 0xFF, port: 0xA1); /* Overkill */
283 outb(value: 0xFE, port: 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(port: acpi_regs_addr);
289 bm_status &= 1 << 4;
290 while (bm_status && bm_timeout) {
291 outw(value: 1 << 4, port: acpi_regs_addr);
292 bm_timeout--;
293 bm_status = inw(port: 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(value: 3, port: 0x22);
301 } else if ((pr != NULL) && pr->flags.bm_control) {
302 /* Disable bus master arbitration */
303 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, value: 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, value: 0);
327 do_powersaver(cx_address: cx->address, mults_index, dir);
328 } else {
329 do_powersaver(cx_address: 0, mults_index, dir);
330 }
331 break;
332 }
333
334 if (longhaul_flags & USE_NORTHBRIDGE) {
335 /* Enable arbiters */
336 outb(value: 0, port: 0x22);
337 } else if ((pr != NULL) && pr->flags.bm_control) {
338 /* Enable bus master arbitration */
339 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, value: 0);
340 }
341 outb(value: pic2_mask, port: 0xA1); /* restore mask */
342 outb(value: pic1_mask, port: 0x21);
343
344 local_irq_restore(flags);
345 preempt_enable();
346
347 freqs.new = calc_speed(mult: 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(msecs: 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(msecs: 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(msecs: 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
406static 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
424static 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(mult: maxmult);
462 lowest_speed = calc_speed(mult: 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(n: numscales + 1, size: 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(mult: ratio);
489 longhaul_table[k].driver_data = j;
490 k++;
491 }
492 if (k <= 1) {
493 kfree(objp: 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
528static 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
619static 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, table_index: i);
644 current_vid = vid;
645 msleep(msecs: 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
660static unsigned int longhaul_get(unsigned int cpu)
661{
662 if (cpu)
663 return 0;
664 return calc_speed(mult: longhaul_get_cpu_mult());
665}
666
667static 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(handle: 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 */
681static 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, device: 0x7259, NULL);
704 }
705 if (dev != NULL) {
706 /* Enable access to port 0x22 */
707 pci_read_config_byte(dev, where: reg, val: &pci_cmd);
708 if (!(pci_cmd & 1<<7)) {
709 pci_cmd |= 1<<7;
710 pci_write_config_byte(dev, where: reg, val: pci_cmd);
711 pci_read_config_byte(dev, where: reg, val: &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
723static 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, where: 0xec, val: &pci_cmd);
737 pci_cmd &= ~(1 << 2);
738 pci_write_config_byte(dev, where: 0xec, val: pci_cmd);
739 pci_read_config_byte(dev, where: 0xe4, val: &pci_cmd);
740 pci_cmd &= ~(1 << 7);
741 pci_write_config_byte(dev, where: 0xe4, val: pci_cmd);
742 pci_read_config_byte(dev, where: 0xe5, val: &pci_cmd);
743 pci_cmd |= 1 << 7;
744 pci_write_config_byte(dev, where: 0xe5, val: pci_cmd);
745 /* Get address of ACPI registers block*/
746 pci_read_config_byte(dev, where: 0x81, val: &pci_cmd);
747 if (pci_cmd & 1 << 7) {
748 pci_read_config_dword(dev, where: 0x88, val: &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
759static 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, descending_callback: &longhaul_walk_callback, NULL,
861 NULL, return_value: (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
902static 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
911static const struct x86_cpu_id longhaul_id[] = {
912 X86_MATCH_VENDOR_FAM(CENTAUR, 6, NULL),
913 {}
914};
915MODULE_DEVICE_TABLE(x86cpu, longhaul_id);
916
917static int __init longhaul_init(void)
918{
919 struct cpuinfo_x86 *c = &cpu_data(0);
920
921 if (!x86_match_cpu(match: 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(driver_data: &longhaul_driver);
943 case 10:
944 pr_err("Use acpi-cpufreq driver for VIA C7\n");
945 }
946
947 return -ENODEV;
948}
949
950
951static void __exit longhaul_exit(void)
952{
953 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu: 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: &freqs);
965 longhaul_setstate(policy, table_index: i);
966 cpufreq_freq_transition_end(policy, freqs: &freqs, transition_failed: 0);
967 break;
968 }
969 }
970
971 cpufreq_cpu_put(policy);
972 cpufreq_unregister_driver(driver_data: &longhaul_driver);
973 kfree(objp: 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. */
979module_param(disable_acpi_c3, int, 0644);
980MODULE_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. */
983module_param(scale_voltage, int, 0644);
984MODULE_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. */
988module_param(revid_errata, int, 0644);
989MODULE_PARM_DESC(revid_errata, "Ignore CPU Revision ID");
990/* By default driver is disabled to prevent incompatible
991 * system freeze. */
992module_param(enable, int, 0644);
993MODULE_PARM_DESC(enable, "Enable driver");
994
995MODULE_AUTHOR("Dave Jones");
996MODULE_DESCRIPTION("Longhaul driver for VIA Cyrix processors.");
997MODULE_LICENSE("GPL");
998
999late_initcall(longhaul_init);
1000module_exit(longhaul_exit);
1001

source code of linux/drivers/cpufreq/longhaul.c