GNU Linux-libre 4.4.289-gnu1
[releases.git] / drivers / cpufreq / powernow-k7.c
1 /*
2  *  AMD K7 Powernow driver.
3  *  (C) 2003 Dave Jones on behalf of SuSE Labs.
4  *
5  *  Licensed under the terms of the GNU GPL License version 2.
6  *  Based upon datasheets & sample CPUs kindly provided by AMD.
7  *
8  * Errata 5:
9  *  CPU may fail to execute a FID/VID change in presence of interrupt.
10  *  - We cli/sti on stepping A0 CPUs around the FID/VID transition.
11  * Errata 15:
12  *  CPU with half frequency multipliers may hang upon wakeup from disconnect.
13  *  - We disable half multipliers if ACPI is used on A0 stepping CPUs.
14  */
15
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/moduleparam.h>
19 #include <linux/init.h>
20 #include <linux/cpufreq.h>
21 #include <linux/slab.h>
22 #include <linux/string.h>
23 #include <linux/dmi.h>
24 #include <linux/timex.h>
25 #include <linux/io.h>
26
27 #include <asm/timer.h>          /* Needed for recalibrate_cpu_khz() */
28 #include <asm/msr.h>
29 #include <asm/cpu_device_id.h>
30
31 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
32 #include <linux/acpi.h>
33 #include <acpi/processor.h>
34 #endif
35
36 #include "powernow-k7.h"
37
38 #define PFX "powernow: "
39
40
41 struct psb_s {
42         u8 signature[10];
43         u8 tableversion;
44         u8 flags;
45         u16 settlingtime;
46         u8 reserved1;
47         u8 numpst;
48 };
49
50 struct pst_s {
51         u32 cpuid;
52         u8 fsbspeed;
53         u8 maxfid;
54         u8 startvid;
55         u8 numpstates;
56 };
57
58 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
59 union powernow_acpi_control_t {
60         struct {
61                 unsigned long fid:5,
62                         vid:5,
63                         sgtc:20,
64                         res1:2;
65         } bits;
66         unsigned long val;
67 };
68 #endif
69
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
78 /* divide by 10 to get FID. */
79 static const int fid_codes[32] = {
80     110, 115, 120, 125, 50, 55, 60, 65,
81     70, 75, 80, 85, 90, 95, 100, 105,
82     30, 190, 40, 200, 130, 135, 140, 210,
83     150, 225, 160, 165, 170, 180, -1, -1,
84 };
85
86 /* This parameter is used in order to force ACPI instead of legacy method for
87  * configuration purpose.
88  */
89
90 static int acpi_force;
91
92 static struct cpufreq_frequency_table *powernow_table;
93
94 static unsigned int can_scale_bus;
95 static unsigned int can_scale_vid;
96 static unsigned int minimum_speed = -1;
97 static unsigned int maximum_speed;
98 static unsigned int number_scales;
99 static unsigned int fsb;
100 static unsigned int latency;
101 static char have_a0;
102
103 static int check_fsb(unsigned int fsbspeed)
104 {
105         int delta;
106         unsigned int f = fsb / 1000;
107
108         delta = (fsbspeed > f) ? fsbspeed - f : f - fsbspeed;
109         return delta < 5;
110 }
111
112 static const struct x86_cpu_id powernow_k7_cpuids[] = {
113         { X86_VENDOR_AMD, 6, },
114         {}
115 };
116 MODULE_DEVICE_TABLE(x86cpu, powernow_k7_cpuids);
117
118 static int check_powernow(void)
119 {
120         struct cpuinfo_x86 *c = &cpu_data(0);
121         unsigned int maxei, eax, ebx, ecx, edx;
122
123         if (!x86_match_cpu(powernow_k7_cpuids))
124                 return 0;
125
126         /* Get maximum capabilities */
127         maxei = cpuid_eax(0x80000000);
128         if (maxei < 0x80000007) {       /* Any powernow info ? */
129 #ifdef MODULE
130                 printk(KERN_INFO PFX "No powernow capabilities detected\n");
131 #endif
132                 return 0;
133         }
134
135         if ((c->x86_model == 6) && (c->x86_stepping == 0)) {
136                 printk(KERN_INFO PFX "K7 660[A0] core detected, "
137                                 "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 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
167 static void invalidate_entry(unsigned int entry)
168 {
169         powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
170 }
171 #endif
172
173 static int get_ranges(unsigned char *pst)
174 {
175         unsigned int j;
176         unsigned int speed;
177         u8 fid, vid;
178
179         powernow_table = kzalloc((sizeof(*powernow_table) *
180                                 (number_scales + 1)), GFP_KERNEL);
181         if (!powernow_table)
182                 return -ENOMEM;
183
184         for (j = 0 ; j < number_scales; j++) {
185                 fid = *pst++;
186
187                 powernow_table[j].frequency = (fsb * fid_codes[fid]) / 10;
188                 powernow_table[j].driver_data = fid; /* lower 8 bits */
189
190                 speed = powernow_table[j].frequency;
191
192                 if ((fid_codes[fid] % 10) == 5) {
193 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
194                         if (have_a0 == 1)
195                                 invalidate_entry(j);
196 #endif
197                 }
198
199                 if (speed < minimum_speed)
200                         minimum_speed = speed;
201                 if (speed > maximum_speed)
202                         maximum_speed = speed;
203
204                 vid = *pst++;
205                 powernow_table[j].driver_data |= (vid << 8); /* upper 8 bits */
206
207                 pr_debug("   FID: 0x%x (%d.%dx [%dMHz])  "
208                          "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
209                          fid_codes[fid] % 10, speed/1000, vid,
210                          mobile_vid_table[vid]/1000,
211                          mobile_vid_table[vid]%1000);
212         }
213         powernow_table[number_scales].frequency = CPUFREQ_TABLE_END;
214         powernow_table[number_scales].driver_data = 0;
215
216         return 0;
217 }
218
219
220 static void change_FID(int fid)
221 {
222         union msr_fidvidctl fidvidctl;
223
224         rdmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
225         if (fidvidctl.bits.FID != fid) {
226                 fidvidctl.bits.SGTC = latency;
227                 fidvidctl.bits.FID = fid;
228                 fidvidctl.bits.VIDC = 0;
229                 fidvidctl.bits.FIDC = 1;
230                 wrmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
231         }
232 }
233
234
235 static void change_VID(int vid)
236 {
237         union msr_fidvidctl fidvidctl;
238
239         rdmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
240         if (fidvidctl.bits.VID != vid) {
241                 fidvidctl.bits.SGTC = latency;
242                 fidvidctl.bits.VID = vid;
243                 fidvidctl.bits.FIDC = 0;
244                 fidvidctl.bits.VIDC = 1;
245                 wrmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
246         }
247 }
248
249
250 static int powernow_target(struct cpufreq_policy *policy, unsigned int index)
251 {
252         u8 fid, vid;
253         struct cpufreq_freqs freqs;
254         union msr_fidvidstatus fidvidstatus;
255         int cfid;
256
257         /* fid are the lower 8 bits of the index we stored into
258          * the cpufreq frequency table in powernow_decode_bios,
259          * vid are the upper 8 bits.
260          */
261
262         fid = powernow_table[index].driver_data & 0xFF;
263         vid = (powernow_table[index].driver_data & 0xFF00) >> 8;
264
265         rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
266         cfid = fidvidstatus.bits.CFID;
267         freqs.old = fsb * fid_codes[cfid] / 10;
268
269         freqs.new = powernow_table[index].frequency;
270
271         /* Now do the magic poking into the MSRs.  */
272
273         if (have_a0 == 1)       /* A0 errata 5 */
274                 local_irq_disable();
275
276         if (freqs.old > freqs.new) {
277                 /* Going down, so change FID first */
278                 change_FID(fid);
279                 change_VID(vid);
280         } else {
281                 /* Going up, so change VID first */
282                 change_VID(vid);
283                 change_FID(fid);
284         }
285
286
287         if (have_a0 == 1)
288                 local_irq_enable();
289
290         return 0;
291 }
292
293
294 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
295
296 static struct acpi_processor_performance *acpi_processor_perf;
297
298 static int powernow_acpi_init(void)
299 {
300         int i;
301         int retval = 0;
302         union powernow_acpi_control_t pc;
303
304         if (acpi_processor_perf != NULL && powernow_table != NULL) {
305                 retval = -EINVAL;
306                 goto err0;
307         }
308
309         acpi_processor_perf = kzalloc(sizeof(*acpi_processor_perf), GFP_KERNEL);
310         if (!acpi_processor_perf) {
311                 retval = -ENOMEM;
312                 goto err0;
313         }
314
315         if (!zalloc_cpumask_var(&acpi_processor_perf->shared_cpu_map,
316                                                                 GFP_KERNEL)) {
317                 retval = -ENOMEM;
318                 goto err05;
319         }
320
321         if (acpi_processor_register_performance(acpi_processor_perf, 0)) {
322                 retval = -EIO;
323                 goto err1;
324         }
325
326         if (acpi_processor_perf->control_register.space_id !=
327                         ACPI_ADR_SPACE_FIXED_HARDWARE) {
328                 retval = -ENODEV;
329                 goto err2;
330         }
331
332         if (acpi_processor_perf->status_register.space_id !=
333                         ACPI_ADR_SPACE_FIXED_HARDWARE) {
334                 retval = -ENODEV;
335                 goto err2;
336         }
337
338         number_scales = acpi_processor_perf->state_count;
339
340         if (number_scales < 2) {
341                 retval = -ENODEV;
342                 goto err2;
343         }
344
345         powernow_table = kzalloc((sizeof(*powernow_table) *
346                                 (number_scales + 1)), GFP_KERNEL);
347         if (!powernow_table) {
348                 retval = -ENOMEM;
349                 goto err2;
350         }
351
352         pc.val = (unsigned long) acpi_processor_perf->states[0].control;
353         for (i = 0; i < number_scales; i++) {
354                 u8 fid, vid;
355                 struct acpi_processor_px *state =
356                         &acpi_processor_perf->states[i];
357                 unsigned int speed, speed_mhz;
358
359                 pc.val = (unsigned long) state->control;
360                 pr_debug("acpi:  P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
361                          i,
362                          (u32) state->core_frequency,
363                          (u32) state->power,
364                          (u32) state->transition_latency,
365                          (u32) state->control,
366                          pc.bits.sgtc);
367
368                 vid = pc.bits.vid;
369                 fid = pc.bits.fid;
370
371                 powernow_table[i].frequency = fsb * fid_codes[fid] / 10;
372                 powernow_table[i].driver_data = fid; /* lower 8 bits */
373                 powernow_table[i].driver_data |= (vid << 8); /* upper 8 bits */
374
375                 speed = powernow_table[i].frequency;
376                 speed_mhz = speed / 1000;
377
378                 /* processor_perflib will multiply the MHz value by 1000 to
379                  * get a KHz value (e.g. 1266000). However, powernow-k7 works
380                  * with true KHz values (e.g. 1266768). To ensure that all
381                  * powernow frequencies are available, we must ensure that
382                  * ACPI doesn't restrict them, so we round up the MHz value
383                  * to ensure that perflib's computed KHz value is greater than
384                  * or equal to powernow's KHz value.
385                  */
386                 if (speed % 1000 > 0)
387                         speed_mhz++;
388
389                 if ((fid_codes[fid] % 10) == 5) {
390                         if (have_a0 == 1)
391                                 invalidate_entry(i);
392                 }
393
394                 pr_debug("   FID: 0x%x (%d.%dx [%dMHz])  "
395                          "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
396                          fid_codes[fid] % 10, speed_mhz, vid,
397                          mobile_vid_table[vid]/1000,
398                          mobile_vid_table[vid]%1000);
399
400                 if (state->core_frequency != speed_mhz) {
401                         state->core_frequency = speed_mhz;
402                         pr_debug("   Corrected ACPI frequency to %d\n",
403                                 speed_mhz);
404                 }
405
406                 if (latency < pc.bits.sgtc)
407                         latency = pc.bits.sgtc;
408
409                 if (speed < minimum_speed)
410                         minimum_speed = speed;
411                 if (speed > maximum_speed)
412                         maximum_speed = speed;
413         }
414
415         powernow_table[i].frequency = CPUFREQ_TABLE_END;
416         powernow_table[i].driver_data = 0;
417
418         /* notify BIOS that we exist */
419         acpi_processor_notify_smm(THIS_MODULE);
420
421         return 0;
422
423 err2:
424         acpi_processor_unregister_performance(0);
425 err1:
426         free_cpumask_var(acpi_processor_perf->shared_cpu_map);
427 err05:
428         kfree(acpi_processor_perf);
429 err0:
430         printk(KERN_WARNING PFX "ACPI perflib can not be used on "
431                         "this platform\n");
432         acpi_processor_perf = NULL;
433         return retval;
434 }
435 #else
436 static int powernow_acpi_init(void)
437 {
438         printk(KERN_INFO PFX "no support for ACPI processor found."
439                "  Please recompile your kernel with ACPI processor\n");
440         return -EINVAL;
441 }
442 #endif
443
444 static void print_pst_entry(struct pst_s *pst, unsigned int j)
445 {
446         pr_debug("PST:%d (@%p)\n", j, pst);
447         pr_debug(" cpuid: 0x%x  fsb: %d  maxFID: 0x%x  startvid: 0x%x\n",
448                 pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid);
449 }
450
451 static int powernow_decode_bios(int maxfid, int startvid)
452 {
453         struct psb_s *psb;
454         struct pst_s *pst;
455         unsigned int i, j;
456         unsigned char *p;
457         unsigned int etuple;
458         unsigned int ret;
459
460         etuple = cpuid_eax(0x80000001);
461
462         for (i = 0xC0000; i < 0xffff0 ; i += 16) {
463
464                 p = phys_to_virt(i);
465
466                 if (memcmp(p, "AMDK7PNOW!",  10) == 0) {
467                         pr_debug("Found PSB header at %p\n", p);
468                         psb = (struct psb_s *) p;
469                         pr_debug("Table version: 0x%x\n", psb->tableversion);
470                         if (psb->tableversion != 0x12) {
471                                 printk(KERN_INFO PFX "Sorry, only v1.2 tables"
472                                                 " supported right now\n");
473                                 return -ENODEV;
474                         }
475
476                         pr_debug("Flags: 0x%x\n", psb->flags);
477                         if ((psb->flags & 1) == 0)
478                                 pr_debug("Mobile voltage regulator\n");
479                         else
480                                 pr_debug("Desktop voltage regulator\n");
481
482                         latency = psb->settlingtime;
483                         if (latency < 100) {
484                                 printk(KERN_INFO PFX "BIOS set settling time "
485                                                 "to %d microseconds. "
486                                                 "Should be at least 100. "
487                                                 "Correcting.\n", latency);
488                                 latency = 100;
489                         }
490                         pr_debug("Settling Time: %d microseconds.\n",
491                                         psb->settlingtime);
492                         pr_debug("Has %d PST tables. (Only dumping ones "
493                                         "relevant to this CPU).\n",
494                                         psb->numpst);
495
496                         p += sizeof(*psb);
497
498                         pst = (struct pst_s *) p;
499
500                         for (j = 0; j < psb->numpst; j++) {
501                                 pst = (struct pst_s *) p;
502                                 number_scales = pst->numpstates;
503
504                                 if ((etuple == pst->cpuid) &&
505                                     check_fsb(pst->fsbspeed) &&
506                                     (maxfid == pst->maxfid) &&
507                                     (startvid == pst->startvid)) {
508                                         print_pst_entry(pst, j);
509                                         p = (char *)pst + sizeof(*pst);
510                                         ret = get_ranges(p);
511                                         return ret;
512                                 } else {
513                                         unsigned int k;
514                                         p = (char *)pst + sizeof(*pst);
515                                         for (k = 0; k < number_scales; k++)
516                                                 p += 2;
517                                 }
518                         }
519                         printk(KERN_INFO PFX "No PST tables match this cpuid "
520                                         "(0x%x)\n", etuple);
521                         printk(KERN_INFO PFX "This is indicative of a broken "
522                                         "BIOS.\n");
523
524                         return -EINVAL;
525                 }
526                 p++;
527         }
528
529         return -ENODEV;
530 }
531
532
533 /*
534  * We use the fact that the bus frequency is somehow
535  * a multiple of 100000/3 khz, then we compute sgtc according
536  * to this multiple.
537  * That way, we match more how AMD thinks all of that work.
538  * We will then get the same kind of behaviour already tested under
539  * the "well-known" other OS.
540  */
541 static int fixup_sgtc(void)
542 {
543         unsigned int sgtc;
544         unsigned int m;
545
546         m = fsb / 3333;
547         if ((m % 10) >= 5)
548                 m += 5;
549
550         m /= 10;
551
552         sgtc = 100 * m * latency;
553         sgtc = sgtc / 3;
554         if (sgtc > 0xfffff) {
555                 printk(KERN_WARNING PFX "SGTC too large %d\n", sgtc);
556                 sgtc = 0xfffff;
557         }
558         return sgtc;
559 }
560
561 static unsigned int powernow_get(unsigned int cpu)
562 {
563         union msr_fidvidstatus fidvidstatus;
564         unsigned int cfid;
565
566         if (cpu)
567                 return 0;
568         rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
569         cfid = fidvidstatus.bits.CFID;
570
571         return fsb * fid_codes[cfid] / 10;
572 }
573
574
575 static int acer_cpufreq_pst(const struct dmi_system_id *d)
576 {
577         printk(KERN_WARNING PFX
578                 "%s laptop with broken PST tables in BIOS detected.\n",
579                 d->ident);
580         printk(KERN_WARNING PFX
581                 "You need to downgrade to 3A21 (09/09/2002), or try a newer "
582                 "BIOS than 3A71 (01/20/2003)\n");
583         printk(KERN_WARNING PFX
584                 "cpufreq scaling has been disabled as a result of this.\n");
585         return 0;
586 }
587
588 /*
589  * Some Athlon laptops have really fucked PST tables.
590  * A BIOS update is all that can save them.
591  * Mention this, and disable cpufreq.
592  */
593 static struct dmi_system_id powernow_dmi_table[] = {
594         {
595                 .callback = acer_cpufreq_pst,
596                 .ident = "Acer Aspire",
597                 .matches = {
598                         DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"),
599                         DMI_MATCH(DMI_BIOS_VERSION, "3A71"),
600                 },
601         },
602         { }
603 };
604
605 static int powernow_cpu_init(struct cpufreq_policy *policy)
606 {
607         union msr_fidvidstatus fidvidstatus;
608         int result;
609
610         if (policy->cpu != 0)
611                 return -ENODEV;
612
613         rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
614
615         recalibrate_cpu_khz();
616
617         fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID];
618         if (!fsb) {
619                 printk(KERN_WARNING PFX "can not determine bus frequency\n");
620                 return -EINVAL;
621         }
622         pr_debug("FSB: %3dMHz\n", fsb/1000);
623
624         if (dmi_check_system(powernow_dmi_table) || acpi_force) {
625                 printk(KERN_INFO PFX "PSB/PST known to be broken.  "
626                                 "Trying ACPI instead\n");
627                 result = powernow_acpi_init();
628         } else {
629                 result = powernow_decode_bios(fidvidstatus.bits.MFID,
630                                 fidvidstatus.bits.SVID);
631                 if (result) {
632                         printk(KERN_INFO PFX "Trying ACPI perflib\n");
633                         maximum_speed = 0;
634                         minimum_speed = -1;
635                         latency = 0;
636                         result = powernow_acpi_init();
637                         if (result) {
638                                 printk(KERN_INFO PFX
639                                         "ACPI and legacy methods failed\n");
640                         }
641                 } else {
642                         /* SGTC use the bus clock as timer */
643                         latency = fixup_sgtc();
644                         printk(KERN_INFO PFX "SGTC: %d\n", latency);
645                 }
646         }
647
648         if (result)
649                 return result;
650
651         printk(KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n",
652                                 minimum_speed/1000, maximum_speed/1000);
653
654         policy->cpuinfo.transition_latency =
655                 cpufreq_scale(2000000UL, fsb, latency);
656
657         return cpufreq_table_validate_and_show(policy, powernow_table);
658 }
659
660 static int powernow_cpu_exit(struct cpufreq_policy *policy)
661 {
662 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
663         if (acpi_processor_perf) {
664                 acpi_processor_unregister_performance(0);
665                 free_cpumask_var(acpi_processor_perf->shared_cpu_map);
666                 kfree(acpi_processor_perf);
667         }
668 #endif
669
670         kfree(powernow_table);
671         return 0;
672 }
673
674 static struct cpufreq_driver powernow_driver = {
675         .verify         = cpufreq_generic_frequency_table_verify,
676         .target_index   = powernow_target,
677         .get            = powernow_get,
678 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
679         .bios_limit     = acpi_processor_get_bios_limit,
680 #endif
681         .init           = powernow_cpu_init,
682         .exit           = powernow_cpu_exit,
683         .name           = "powernow-k7",
684         .attr           = cpufreq_generic_attr,
685 };
686
687 static int __init powernow_init(void)
688 {
689         if (check_powernow() == 0)
690                 return -ENODEV;
691         return cpufreq_register_driver(&powernow_driver);
692 }
693
694
695 static void __exit powernow_exit(void)
696 {
697         cpufreq_unregister_driver(&powernow_driver);
698 }
699
700 module_param(acpi_force,  int, 0444);
701 MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");
702
703 MODULE_AUTHOR("Dave Jones");
704 MODULE_DESCRIPTION("Powernow driver for AMD K7 processors.");
705 MODULE_LICENSE("GPL");
706
707 late_initcall(powernow_init);
708 module_exit(powernow_exit);
709