1 /*
2 * AMD K7 Powernow driver.
3 * (C) 2003 Dave Jones <davej@codemonkey.org.uk> on behalf of SuSE Labs.
4 * (C) 2003-2004 Dave Jones <davej@redhat.com>
5 *
6 * Licensed under the terms of the GNU GPL License version 2.
7 * Based upon datasheets & sample CPUs kindly provided by AMD.
8 *
9 * Errata 5: Processor 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: Processors with half frequency multipliers may hang upon wakeup from disconnect.
12 * - We disable half multipliers if ACPI is used on A0 stepping CPUs.
13 */
14
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/moduleparam.h>
18 #include <linux/init.h>
19 #include <linux/cpufreq.h>
20 #include <linux/slab.h>
21 #include <linux/string.h>
22 #include <linux/dmi.h>
23
24 #include <asm/msr.h>
25 #include <asm/timer.h>
26 #include <asm/timex.h>
27 #include <asm/io.h>
28 #include <asm/system.h>
29
30 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
31 #include <linux/acpi.h>
32 #include <acpi/processor.h>
33 #endif
34
35 #include "powernow-k7.h"
36
37 #define PFX "powernow: "
38
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 #ifdef CONFIG_CPU_FREQ_DEBUG
70 /* divide by 1000 to get VCore voltage in V. */
71 static const int mobile_vid_table[32] = {
72 2000, 1950, 1900, 1850, 1800, 1750, 1700, 1650,
73 1600, 1550, 1500, 1450, 1400, 1350, 1300, 0,
74 1275, 1250, 1225, 1200, 1175, 1150, 1125, 1100,
75 1075, 1050, 1025, 1000, 975, 950, 925, 0,
76 };
77 #endif
78
79 /* divide by 10 to get FID. */
80 static const int fid_codes[32] = {
81 110, 115, 120, 125, 50, 55, 60, 65,
82 70, 75, 80, 85, 90, 95, 100, 105,
83 30, 190, 40, 200, 130, 135, 140, 210,
84 150, 225, 160, 165, 170, 180, -1, -1,
85 };
86
87 /* This parameter is used in order to force ACPI instead of legacy method for
88 * configuration purpose.
89 */
90
91 static int acpi_force;
92
93 static struct cpufreq_frequency_table *powernow_table;
94
95 static unsigned int can_scale_bus;
96 static unsigned int can_scale_vid;
97 static unsigned int minimum_speed=-1;
98 static unsigned int maximum_speed;
99 static unsigned int number_scales;
100 static unsigned int fsb;
101 static unsigned int latency;
102 static char have_a0;
103
104 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "powernow-k7", msg)
105
106 static int check_fsb(unsigned int fsbspeed)
107 {
108 int delta;
109 unsigned int f = fsb / 1000;
110
111 delta = (fsbspeed > f) ? fsbspeed - f : f - fsbspeed;
112 return (delta < 5);
113 }
114
115 static int check_powernow(void)
116 {
117 struct cpuinfo_x86 *c = &cpu_data(0);
118 unsigned int maxei, eax, ebx, ecx, edx;
119
120 if ((c->x86_vendor != X86_VENDOR_AMD) || (c->x86 !=6)) {
121 #ifdef MODULE
122 printk (KERN_INFO PFX "This module only works with AMD K7 CPUs\n");
123 #endif
124 return 0;
125 }
126
127 /* Get maximum capabilities */
128 maxei = cpuid_eax (0x80000000);
129 if (maxei < 0x80000007) { /* Any powernow info ? */
130 #ifdef MODULE
131 printk (KERN_INFO PFX "No powernow capabilities detected\n");
132 #endif
133 return 0;
134 }
135
136 if ((c->x86_model == 6) && (c->x86_mask == 0)) {
137 printk (KERN_INFO PFX "K7 660[A0] core detected, enabling errata workarounds\n");
138 have_a0 = 1;
139 }
140
141 cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
142
143 /* Check we can actually do something before we say anything.*/
144 if (!(edx & (1 << 1 | 1 << 2)))
145 return 0;
146
147 printk (KERN_INFO PFX "PowerNOW! Technology present. Can scale: ");
148
149 if (edx & 1 << 1) {
150 printk ("frequency");
151 can_scale_bus=1;
152 }
153
154 if ((edx & (1 << 1 | 1 << 2)) == 0x6)
155 printk (" and ");
156
157 if (edx & 1 << 2) {
158 printk ("voltage");
159 can_scale_vid=1;
160 }
161
162 printk (".\n");
163 return 1;
164 }
165
166
167 static int get_ranges (unsigned char *pst)
168 {
169 unsigned int j;
170 unsigned int speed;
171 u8 fid, vid;
172
173 powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) * (number_scales + 1)), GFP_KERNEL);
174 if (!powernow_table)
175 return -ENOMEM;
176
177 for (j=0 ; j < number_scales; j++) {
178 fid = *pst++;
179
180 powernow_table[j].frequency = (fsb * fid_codes[fid]) / 10;
181 powernow_table[j].index = fid; /* lower 8 bits */
182
183 speed = powernow_table[j].frequency;
184
185 if ((fid_codes[fid] % 10)==5) {
186 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
187 if (have_a0 == 1)
188 powernow_table[j].frequency = CPUFREQ_ENTRY_INVALID;
189 #endif
190 }
191
192 if (speed < minimum_speed)
193 minimum_speed = speed;
194 if (speed > maximum_speed)
195 maximum_speed = speed;
196
197 vid = *pst++;
198 powernow_table[j].index |= (vid << 8); /* upper 8 bits */
199
200 dprintk (" FID: 0x%x (%d.%dx [%dMHz]) "
201 "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
202 fid_codes[fid] % 10, speed/1000, vid,
203 mobile_vid_table[vid]/1000,
204 mobile_vid_table[vid]%1000);
205 }
206 powernow_table[number_scales].frequency = CPUFREQ_TABLE_END;
207 powernow_table[number_scales].index = 0;
208
209 return 0;
210 }
211
212
213 static void change_FID(int fid)
214 {
215 union msr_fidvidctl fidvidctl;
216
217 rdmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val);
218 if (fidvidctl.bits.FID != fid) {
219 fidvidctl.bits.SGTC = latency;
220 fidvidctl.bits.FID = fid;
221 fidvidctl.bits.VIDC = 0;
222 fidvidctl.bits.FIDC = 1;
223 wrmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val);
224 }
225 }
226
227
228 static void change_VID(int vid)
229 {
230 union msr_fidvidctl fidvidctl;
231
232 rdmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val);
233 if (fidvidctl.bits.VID != vid) {
234 fidvidctl.bits.SGTC = latency;
235 fidvidctl.bits.VID = vid;
236 fidvidctl.bits.FIDC = 0;
237 fidvidctl.bits.VIDC = 1;
238 wrmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val);
239 }
240 }
241
242
243 static void change_speed (unsigned int index)
244 {
245 u8 fid, vid;
246 struct cpufreq_freqs freqs;
247 union msr_fidvidstatus fidvidstatus;
248 int cfid;
249
250 /* fid are the lower 8 bits of the index we stored into
251 * the cpufreq frequency table in powernow_decode_bios,
252 * vid are the upper 8 bits.
253 */
254
255 fid = powernow_table[index].index & 0xFF;
256 vid = (powernow_table[index].index & 0xFF00) >> 8;
257
258 freqs.cpu = 0;
259
260 rdmsrl (MSR_K7_FID_VID_STATUS, fidvidstatus.val);
261 cfid = fidvidstatus.bits.CFID;
262 freqs.old = fsb * fid_codes[cfid] / 10;
263
264 freqs.new = powernow_table[index].frequency;
265
266 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
267
268 /* Now do the magic poking into the MSRs. */
269
270 if (have_a0 == 1) /* A0 errata 5 */
271 local_irq_disable();
272
273 if (freqs.old > freqs.new) {
274 /* Going down, so change FID first */
275 change_FID(fid);
276 change_VID(vid);
277 } else {
278 /* Going up, so change VID first */
279 change_VID(vid);
280 change_FID(fid);
281 }
282
283
284 if (have_a0 == 1)
285 local_irq_enable();
286
287 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
288 }
289
290
291 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
292
293 static struct acpi_processor_performance *acpi_processor_perf;
294
295 static int powernow_acpi_init(void)
296 {
297 int i;
298 int retval = 0;
299 union powernow_acpi_control_t pc;
300
301 if (acpi_processor_perf != NULL && powernow_table != NULL) {
302 retval = -EINVAL;
303 goto err0;
304 }
305
306 acpi_processor_perf = kzalloc(sizeof(struct acpi_processor_performance),
307 GFP_KERNEL);
308 if (!acpi_processor_perf) {
309 retval = -ENOMEM;
310 goto err0;
311 }
312
313 if (acpi_processor_register_performance(acpi_processor_perf, 0)) {
314 retval = -EIO;
315 goto err1;
316 }
317
318 if (acpi_processor_perf->control_register.space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) {
319 retval = -ENODEV;
320 goto err2;
321 }
322
323 if (acpi_processor_perf->status_register.space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) {
324 retval = -ENODEV;
325 goto err2;
326 }
327
328 number_scales = acpi_processor_perf->state_count;
329
330 if (number_scales < 2) {
331 retval = -ENODEV;
332 goto err2;
333 }
334
335 powernow_table = kzalloc((number_scales + 1) * (sizeof(struct cpufreq_frequency_table)), GFP_KERNEL);
336 if (!powernow_table) {
337 retval = -ENOMEM;
338 goto err2;
339 }
340
341 pc.val = (unsigned long) acpi_processor_perf->states[0].control;
342 for (i = 0; i < number_scales; i++) {
343 u8 fid, vid;
344 struct acpi_processor_px *state =
345 &acpi_processor_perf->states[i];
346 unsigned int speed, speed_mhz;
347
348 pc.val = (unsigned long) state->control;
349 dprintk ("acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
350 i,
351 (u32) state->core_frequency,
352 (u32) state->power,
353 (u32) state->transition_latency,
354 (u32) state->control,
355 pc.bits.sgtc);
356
357 vid = pc.bits.vid;
358 fid = pc.bits.fid;
359
360 powernow_table[i].frequency = fsb * fid_codes[fid] / 10;
361 powernow_table[i].index = fid; /* lower 8 bits */
362 powernow_table[i].index |= (vid << 8); /* upper 8 bits */
363
364 speed = powernow_table[i].frequency;
365 speed_mhz = speed / 1000;
366
367 /* processor_perflib will multiply the MHz value by 1000 to
368 * get a KHz value (e.g. 1266000). However, powernow-k7 works
369 * with true KHz values (e.g. 1266768). To ensure that all
370 * powernow frequencies are available, we must ensure that
371 * ACPI doesn't restrict them, so we round up the MHz value
372 * to ensure that perflib's computed KHz value is greater than
373 * or equal to powernow's KHz value.
374 */
375 if (speed % 1000 > 0)
376 speed_mhz++;
377
378 if ((fid_codes[fid] % 10)==5) {
379 if (have_a0 == 1)
380 powernow_table[i].frequency = CPUFREQ_ENTRY_INVALID;
381 }
382
383 dprintk (" FID: 0x%x (%d.%dx [%dMHz]) "
384 "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
385 fid_codes[fid] % 10, speed_mhz, vid,
386 mobile_vid_table[vid]/1000,
387 mobile_vid_table[vid]%1000);
388
389 if (state->core_frequency != speed_mhz) {
390 state->core_frequency = speed_mhz;
391 dprintk(" Corrected ACPI frequency to %d\n",
392 speed_mhz);
393 }
394
395 if (latency < pc.bits.sgtc)
396 latency = pc.bits.sgtc;
397
398 if (speed < minimum_speed)
399 minimum_speed = speed;
400 if (speed > maximum_speed)
401 maximum_speed = speed;
402 }
403
404 powernow_table[i].frequency = CPUFREQ_TABLE_END;
405 powernow_table[i].index = 0;
406
407 /* notify BIOS that we exist */
408 acpi_processor_notify_smm(THIS_MODULE);
409
410 return 0;
411
412 err2:
413 acpi_processor_unregister_performance(acpi_processor_perf, 0);
414 err1:
415 kfree(acpi_processor_perf);
416 err0:
417 printk(KERN_WARNING PFX "ACPI perflib can not be used in this platform\n");
418 acpi_processor_perf = NULL;
419 return retval;
420 }
421 #else
422 static int powernow_acpi_init(void)
423 {
424 printk(KERN_INFO PFX "no support for ACPI processor found."
425 " Please recompile your kernel with ACPI processor\n");
426 return -EINVAL;
427 }
428 #endif
429
430 static int powernow_decode_bios (int maxfid, int startvid)
431 {
432 struct psb_s *psb;
433 struct pst_s *pst;
434 unsigned int i, j;
435 unsigned char *p;
436 unsigned int etuple;
437 unsigned int ret;
438
439 etuple = cpuid_eax(0x80000001);
440
441 for (i=0xC0000; i < 0xffff0 ; i+=16) {
442
443 p = phys_to_virt(i);
444
445 if (memcmp(p, "AMDK7PNOW!", 10) == 0){
446 dprintk ("Found PSB header at %p\n", p);
447 psb = (struct psb_s *) p;
448 dprintk ("Table version: 0x%x\n", psb->tableversion);
449 if (psb->tableversion != 0x12) {
450 printk (KERN_INFO PFX "Sorry, only v1.2 tables supported right now\n");
451 return -ENODEV;
452 }
453
454 dprintk ("Flags: 0x%x\n", psb->flags);
455 if ((psb->flags & 1)==0) {
456 dprintk ("Mobile voltage regulator\n");
457 } else {
458 dprintk ("Desktop voltage regulator\n");
459 }
460
461 latency = psb->settlingtime;
462 if (latency < 100) {
463 printk(KERN_INFO PFX "BIOS set settling time to %d microseconds. "
464 "Should be at least 100. Correcting.\n", latency);
465 latency = 100;
466 }
467 dprintk ("Settling Time: %d microseconds.\n", psb->settlingtime);
468 dprintk ("Has %d PST tables. (Only dumping ones relevant to this CPU).\n", psb->numpst);
469
470 p += sizeof (struct psb_s);
471
472 pst = (struct pst_s *) p;
473
474 for (j=0; j<psb->numpst; j++) {
475 pst = (struct pst_s *) p;
476 number_scales = pst->numpstates;
477
478 if ((etuple == pst->cpuid) && check_fsb(pst->fsbspeed) &&
479 (maxfid==pst->maxfid) && (startvid==pst->startvid))
480 {
481 dprintk ("PST:%d (@%p)\n", j, pst);
482 dprintk (" cpuid: 0x%x fsb: %d maxFID: 0x%x startvid: 0x%x\n",
483 pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid);
484
485 ret = get_ranges ((char *) pst + sizeof (struct pst_s));
486 return ret;
487 } else {
488 unsigned int k;
489 p = (char *) pst + sizeof (struct pst_s);
490 for (k=0; k<number_scales; k++)
491 p+=2;
492 }
493 }
494 printk (KERN_INFO PFX "No PST tables match this cpuid (0x%x)\n", etuple);
495 printk (KERN_INFO PFX "This is indicative of a broken BIOS.\n");
496
497 return -EINVAL;
498 }
499 p++;
500 }
501
502 return -ENODEV;
503 }
504
505
506 static int powernow_target (struct cpufreq_policy *policy,
507 unsigned int target_freq,
508 unsigned int relation)
509 {
510 unsigned int newstate;
511
512 if (cpufreq_frequency_table_target(policy, powernow_table, target_freq, relation, &newstate))
513 return -EINVAL;
514
515 change_speed(newstate);
516
517 return 0;
518 }
519
520
521 static int powernow_verify (struct cpufreq_policy *policy)
522 {
523 return cpufreq_frequency_table_verify(policy, powernow_table);
524 }
525
526 /*
527 * We use the fact that the bus frequency is somehow
528 * a multiple of 100000/3 khz, then we compute sgtc according
529 * to this multiple.
530 * That way, we match more how AMD thinks all of that work.
531 * We will then get the same kind of behaviour already tested under
532 * the "well-known" other OS.
533 */
534 static int __init fixup_sgtc(void)
535 {
536 unsigned int sgtc;
537 unsigned int m;
538
539 m = fsb / 3333;
540 if ((m % 10) >= 5)
541 m += 5;
542
543 m /= 10;
544
545 sgtc = 100 * m * latency;
546 sgtc = sgtc / 3;
547 if (sgtc > 0xfffff) {
548 printk(KERN_WARNING PFX "SGTC too large %d\n", sgtc);
549 sgtc = 0xfffff;
550 }
551 return sgtc;
552 }
553
554 static unsigned int powernow_get(unsigned int cpu)
555 {
556 union msr_fidvidstatus fidvidstatus;
557 unsigned int cfid;
558
559 if (cpu)
560 return 0;
561 rdmsrl (MSR_K7_FID_VID_STATUS, fidvidstatus.val);
562 cfid = fidvidstatus.bits.CFID;
563
564 return (fsb * fid_codes[cfid] / 10);
565 }
566
567
568 static int __init acer_cpufreq_pst(const struct dmi_system_id *d)
569 {
570 printk(KERN_WARNING "%s laptop with broken PST tables in BIOS detected.\n", d->ident);
571 printk(KERN_WARNING "You need to downgrade to 3A21 (09/09/2002), or try a newer BIOS than 3A71 (01/20/2003)\n");
572 printk(KERN_WARNING "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 struct dmi_system_id __initdata 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 __init 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 printk(KERN_WARNING PFX "can not determine bus frequency\n");
608 return -EINVAL;
609 }
610 dprintk("FSB: %3dMHz\n", fsb/1000);
611
612 if (dmi_check_system(powernow_dmi_table) || acpi_force) {
613 printk (KERN_INFO PFX "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, fidvidstatus.bits.SVID);
617 if (result) {
618 printk (KERN_INFO PFX "Trying ACPI perflib\n");
619 maximum_speed = 0;
620 minimum_speed = -1;
621 latency = 0;
622 result = powernow_acpi_init();
623 if (result) {
624 printk (KERN_INFO PFX "ACPI and legacy methods failed\n");
625 printk (KERN_INFO PFX "See http://www.codemonkey.org.uk/projects/cpufreq/powernow-k7.html\n");
626 }
627 } else {
628 /* SGTC use the bus clock as timer */
629 latency = fixup_sgtc();
630 printk(KERN_INFO PFX "SGTC: %d\n", latency);
631 }
632 }
633
634 if (result)
635 return result;
636
637 printk (KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n",
638 minimum_speed/1000, maximum_speed/1000);
639
640 policy->cpuinfo.transition_latency = cpufreq_scale(2000000UL, fsb, latency);
641
642 policy->cur = powernow_get(0);
643
644 cpufreq_frequency_table_get_attr(powernow_table, policy->cpu);
645
646 return cpufreq_frequency_table_cpuinfo(policy, powernow_table);
647 }
648
649 static int powernow_cpu_exit (struct cpufreq_policy *policy) {
650 cpufreq_frequency_table_put_attr(policy->cpu);
651
652 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
653 if (acpi_processor_perf) {
654 acpi_processor_unregister_performance(acpi_processor_perf, 0);
655 kfree(acpi_processor_perf);
656 }
657 #endif
658
659 kfree(powernow_table);
660 return 0;
661 }
662
663 static struct freq_attr* powernow_table_attr[] = {
664 &cpufreq_freq_attr_scaling_available_freqs,
665 NULL,
666 };
667
668 static struct cpufreq_driver powernow_driver = {
669 .verify = powernow_verify,
670 .target = powernow_target,
671 .get = powernow_get,
672 .init = powernow_cpu_init,
673 .exit = powernow_cpu_exit,
674 .name = "powernow-k7",
675 .owner = THIS_MODULE,
676 .attr = powernow_table_attr,
677 };
678
679 static int __init powernow_init (void)
680 {
681 if (check_powernow()==0)
682 return -ENODEV;
683 return cpufreq_register_driver(&powernow_driver);
684 }
685
686
687 static void __exit powernow_exit (void)
688 {
689 cpufreq_unregister_driver(&powernow_driver);
690 }
691
692 module_param(acpi_force, int, 0444);
693 MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");
694
695 MODULE_AUTHOR ("Dave Jones <davej@codemonkey.org.uk>");
696 MODULE_DESCRIPTION ("Powernow driver for AMD K7 processors.");
697 MODULE_LICENSE ("GPL");
698
699 late_initcall(powernow_init);
700 module_exit(powernow_exit);
701
702
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