Linux 3.3-rc6
[linux/fpc-iii.git] / drivers / cpufreq / powernow-k7.c
blobd71d9f3723590cd659323e58338ca0c2a7ee9319
1 /*
2 * AMD K7 Powernow driver.
3 * (C) 2003 Dave Jones on behalf of SuSE Labs.
4 * (C) 2003-2004 Dave Jones <davej@redhat.com>
6 * Licensed under the terms of the GNU GPL License version 2.
7 * Based upon datasheets & sample CPUs kindly provided by AMD.
9 * Errata 5:
10 * CPU may fail to execute a FID/VID change in presence of interrupt.
11 * - We cli/sti on stepping A0 CPUs around the FID/VID transition.
12 * Errata 15:
13 * CPU with half frequency multipliers may hang upon wakeup from disconnect.
14 * - We disable half multipliers if ACPI is used on A0 stepping CPUs.
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/init.h>
21 #include <linux/cpufreq.h>
22 #include <linux/slab.h>
23 #include <linux/string.h>
24 #include <linux/dmi.h>
25 #include <linux/timex.h>
26 #include <linux/io.h>
28 #include <asm/timer.h> /* Needed for recalibrate_cpu_khz() */
29 #include <asm/msr.h>
30 #include <asm/system.h>
32 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
33 #include <linux/acpi.h>
34 #include <acpi/processor.h>
35 #endif
37 #include "powernow-k7.h"
39 #define PFX "powernow: "
42 struct psb_s {
43 u8 signature[10];
44 u8 tableversion;
45 u8 flags;
46 u16 settlingtime;
47 u8 reserved1;
48 u8 numpst;
51 struct pst_s {
52 u32 cpuid;
53 u8 fsbspeed;
54 u8 maxfid;
55 u8 startvid;
56 u8 numpstates;
59 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
60 union powernow_acpi_control_t {
61 struct {
62 unsigned long fid:5,
63 vid:5,
64 sgtc:20,
65 res1:2;
66 } bits;
67 unsigned long val;
69 #endif
71 /* divide by 1000 to get VCore voltage in V. */
72 static const int mobile_vid_table[32] = {
73 2000, 1950, 1900, 1850, 1800, 1750, 1700, 1650,
74 1600, 1550, 1500, 1450, 1400, 1350, 1300, 0,
75 1275, 1250, 1225, 1200, 1175, 1150, 1125, 1100,
76 1075, 1050, 1025, 1000, 975, 950, 925, 0,
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,
87 /* This parameter is used in order to force ACPI instead of legacy method for
88 * configuration purpose.
91 static int acpi_force;
93 static struct cpufreq_frequency_table *powernow_table;
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;
104 static int check_fsb(unsigned int fsbspeed)
106 int delta;
107 unsigned int f = fsb / 1000;
109 delta = (fsbspeed > f) ? fsbspeed - f : f - fsbspeed;
110 return delta < 5;
113 static int check_powernow(void)
115 struct cpuinfo_x86 *c = &cpu_data(0);
116 unsigned int maxei, eax, ebx, ecx, edx;
118 if ((c->x86_vendor != X86_VENDOR_AMD) || (c->x86 != 6)) {
119 #ifdef MODULE
120 printk(KERN_INFO PFX "This module only works with "
121 "AMD K7 CPUs\n");
122 #endif
123 return 0;
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;
135 if ((c->x86_model == 6) && (c->x86_mask == 0)) {
136 printk(KERN_INFO PFX "K7 660[A0] core detected, "
137 "enabling errata workarounds\n");
138 have_a0 = 1;
141 cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
143 /* Check we can actually do something before we say anything.*/
144 if (!(edx & (1 << 1 | 1 << 2)))
145 return 0;
147 printk(KERN_INFO PFX "PowerNOW! Technology present. Can scale: ");
149 if (edx & 1 << 1) {
150 printk("frequency");
151 can_scale_bus = 1;
154 if ((edx & (1 << 1 | 1 << 2)) == 0x6)
155 printk(" and ");
157 if (edx & 1 << 2) {
158 printk("voltage");
159 can_scale_vid = 1;
162 printk(".\n");
163 return 1;
166 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
167 static void invalidate_entry(unsigned int entry)
169 powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
171 #endif
173 static int get_ranges(unsigned char *pst)
175 unsigned int j;
176 unsigned int speed;
177 u8 fid, vid;
179 powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) *
180 (number_scales + 1)), GFP_KERNEL);
181 if (!powernow_table)
182 return -ENOMEM;
184 for (j = 0 ; j < number_scales; j++) {
185 fid = *pst++;
187 powernow_table[j].frequency = (fsb * fid_codes[fid]) / 10;
188 powernow_table[j].index = fid; /* lower 8 bits */
190 speed = powernow_table[j].frequency;
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
199 if (speed < minimum_speed)
200 minimum_speed = speed;
201 if (speed > maximum_speed)
202 maximum_speed = speed;
204 vid = *pst++;
205 powernow_table[j].index |= (vid << 8); /* upper 8 bits */
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);
213 powernow_table[number_scales].frequency = CPUFREQ_TABLE_END;
214 powernow_table[number_scales].index = 0;
216 return 0;
220 static void change_FID(int fid)
222 union msr_fidvidctl fidvidctl;
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);
235 static void change_VID(int vid)
237 union msr_fidvidctl fidvidctl;
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);
250 static void change_speed(unsigned int index)
252 u8 fid, vid;
253 struct cpufreq_freqs freqs;
254 union msr_fidvidstatus fidvidstatus;
255 int cfid;
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.
262 fid = powernow_table[index].index & 0xFF;
263 vid = (powernow_table[index].index & 0xFF00) >> 8;
265 freqs.cpu = 0;
267 rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
268 cfid = fidvidstatus.bits.CFID;
269 freqs.old = fsb * fid_codes[cfid] / 10;
271 freqs.new = powernow_table[index].frequency;
273 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
275 /* Now do the magic poking into the MSRs. */
277 if (have_a0 == 1) /* A0 errata 5 */
278 local_irq_disable();
280 if (freqs.old > freqs.new) {
281 /* Going down, so change FID first */
282 change_FID(fid);
283 change_VID(vid);
284 } else {
285 /* Going up, so change VID first */
286 change_VID(vid);
287 change_FID(fid);
291 if (have_a0 == 1)
292 local_irq_enable();
294 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
298 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
300 static struct acpi_processor_performance *acpi_processor_perf;
302 static int powernow_acpi_init(void)
304 int i;
305 int retval = 0;
306 union powernow_acpi_control_t pc;
308 if (acpi_processor_perf != NULL && powernow_table != NULL) {
309 retval = -EINVAL;
310 goto err0;
313 acpi_processor_perf = kzalloc(sizeof(struct acpi_processor_performance),
314 GFP_KERNEL);
315 if (!acpi_processor_perf) {
316 retval = -ENOMEM;
317 goto err0;
320 if (!zalloc_cpumask_var(&acpi_processor_perf->shared_cpu_map,
321 GFP_KERNEL)) {
322 retval = -ENOMEM;
323 goto err05;
326 if (acpi_processor_register_performance(acpi_processor_perf, 0)) {
327 retval = -EIO;
328 goto err1;
331 if (acpi_processor_perf->control_register.space_id !=
332 ACPI_ADR_SPACE_FIXED_HARDWARE) {
333 retval = -ENODEV;
334 goto err2;
337 if (acpi_processor_perf->status_register.space_id !=
338 ACPI_ADR_SPACE_FIXED_HARDWARE) {
339 retval = -ENODEV;
340 goto err2;
343 number_scales = acpi_processor_perf->state_count;
345 if (number_scales < 2) {
346 retval = -ENODEV;
347 goto err2;
350 powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) *
351 (number_scales + 1)), GFP_KERNEL);
352 if (!powernow_table) {
353 retval = -ENOMEM;
354 goto err2;
357 pc.val = (unsigned long) acpi_processor_perf->states[0].control;
358 for (i = 0; i < number_scales; i++) {
359 u8 fid, vid;
360 struct acpi_processor_px *state =
361 &acpi_processor_perf->states[i];
362 unsigned int speed, speed_mhz;
364 pc.val = (unsigned long) state->control;
365 pr_debug("acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
367 (u32) state->core_frequency,
368 (u32) state->power,
369 (u32) state->transition_latency,
370 (u32) state->control,
371 pc.bits.sgtc);
373 vid = pc.bits.vid;
374 fid = pc.bits.fid;
376 powernow_table[i].frequency = fsb * fid_codes[fid] / 10;
377 powernow_table[i].index = fid; /* lower 8 bits */
378 powernow_table[i].index |= (vid << 8); /* upper 8 bits */
380 speed = powernow_table[i].frequency;
381 speed_mhz = speed / 1000;
383 /* processor_perflib will multiply the MHz value by 1000 to
384 * get a KHz value (e.g. 1266000). However, powernow-k7 works
385 * with true KHz values (e.g. 1266768). To ensure that all
386 * powernow frequencies are available, we must ensure that
387 * ACPI doesn't restrict them, so we round up the MHz value
388 * to ensure that perflib's computed KHz value is greater than
389 * or equal to powernow's KHz value.
391 if (speed % 1000 > 0)
392 speed_mhz++;
394 if ((fid_codes[fid] % 10) == 5) {
395 if (have_a0 == 1)
396 invalidate_entry(i);
399 pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) "
400 "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
401 fid_codes[fid] % 10, speed_mhz, vid,
402 mobile_vid_table[vid]/1000,
403 mobile_vid_table[vid]%1000);
405 if (state->core_frequency != speed_mhz) {
406 state->core_frequency = speed_mhz;
407 pr_debug(" Corrected ACPI frequency to %d\n",
408 speed_mhz);
411 if (latency < pc.bits.sgtc)
412 latency = pc.bits.sgtc;
414 if (speed < minimum_speed)
415 minimum_speed = speed;
416 if (speed > maximum_speed)
417 maximum_speed = speed;
420 powernow_table[i].frequency = CPUFREQ_TABLE_END;
421 powernow_table[i].index = 0;
423 /* notify BIOS that we exist */
424 acpi_processor_notify_smm(THIS_MODULE);
426 return 0;
428 err2:
429 acpi_processor_unregister_performance(acpi_processor_perf, 0);
430 err1:
431 free_cpumask_var(acpi_processor_perf->shared_cpu_map);
432 err05:
433 kfree(acpi_processor_perf);
434 err0:
435 printk(KERN_WARNING PFX "ACPI perflib can not be used on "
436 "this platform\n");
437 acpi_processor_perf = NULL;
438 return retval;
440 #else
441 static int powernow_acpi_init(void)
443 printk(KERN_INFO PFX "no support for ACPI processor found."
444 " Please recompile your kernel with ACPI processor\n");
445 return -EINVAL;
447 #endif
449 static void print_pst_entry(struct pst_s *pst, unsigned int j)
451 pr_debug("PST:%d (@%p)\n", j, pst);
452 pr_debug(" cpuid: 0x%x fsb: %d maxFID: 0x%x startvid: 0x%x\n",
453 pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid);
456 static int powernow_decode_bios(int maxfid, int startvid)
458 struct psb_s *psb;
459 struct pst_s *pst;
460 unsigned int i, j;
461 unsigned char *p;
462 unsigned int etuple;
463 unsigned int ret;
465 etuple = cpuid_eax(0x80000001);
467 for (i = 0xC0000; i < 0xffff0 ; i += 16) {
469 p = phys_to_virt(i);
471 if (memcmp(p, "AMDK7PNOW!", 10) == 0) {
472 pr_debug("Found PSB header at %p\n", p);
473 psb = (struct psb_s *) p;
474 pr_debug("Table version: 0x%x\n", psb->tableversion);
475 if (psb->tableversion != 0x12) {
476 printk(KERN_INFO PFX "Sorry, only v1.2 tables"
477 " supported right now\n");
478 return -ENODEV;
481 pr_debug("Flags: 0x%x\n", psb->flags);
482 if ((psb->flags & 1) == 0)
483 pr_debug("Mobile voltage regulator\n");
484 else
485 pr_debug("Desktop voltage regulator\n");
487 latency = psb->settlingtime;
488 if (latency < 100) {
489 printk(KERN_INFO PFX "BIOS set settling time "
490 "to %d microseconds. "
491 "Should be at least 100. "
492 "Correcting.\n", latency);
493 latency = 100;
495 pr_debug("Settling Time: %d microseconds.\n",
496 psb->settlingtime);
497 pr_debug("Has %d PST tables. (Only dumping ones "
498 "relevant to this CPU).\n",
499 psb->numpst);
501 p += sizeof(struct psb_s);
503 pst = (struct pst_s *) p;
505 for (j = 0; j < psb->numpst; j++) {
506 pst = (struct pst_s *) p;
507 number_scales = pst->numpstates;
509 if ((etuple == pst->cpuid) &&
510 check_fsb(pst->fsbspeed) &&
511 (maxfid == pst->maxfid) &&
512 (startvid == pst->startvid)) {
513 print_pst_entry(pst, j);
514 p = (char *)pst + sizeof(struct pst_s);
515 ret = get_ranges(p);
516 return ret;
517 } else {
518 unsigned int k;
519 p = (char *)pst + sizeof(struct pst_s);
520 for (k = 0; k < number_scales; k++)
521 p += 2;
524 printk(KERN_INFO PFX "No PST tables match this cpuid "
525 "(0x%x)\n", etuple);
526 printk(KERN_INFO PFX "This is indicative of a broken "
527 "BIOS.\n");
529 return -EINVAL;
531 p++;
534 return -ENODEV;
538 static int powernow_target(struct cpufreq_policy *policy,
539 unsigned int target_freq,
540 unsigned int relation)
542 unsigned int newstate;
544 if (cpufreq_frequency_table_target(policy, powernow_table, target_freq,
545 relation, &newstate))
546 return -EINVAL;
548 change_speed(newstate);
550 return 0;
554 static int powernow_verify(struct cpufreq_policy *policy)
556 return cpufreq_frequency_table_verify(policy, powernow_table);
560 * We use the fact that the bus frequency is somehow
561 * a multiple of 100000/3 khz, then we compute sgtc according
562 * to this multiple.
563 * That way, we match more how AMD thinks all of that work.
564 * We will then get the same kind of behaviour already tested under
565 * the "well-known" other OS.
567 static int __cpuinit fixup_sgtc(void)
569 unsigned int sgtc;
570 unsigned int m;
572 m = fsb / 3333;
573 if ((m % 10) >= 5)
574 m += 5;
576 m /= 10;
578 sgtc = 100 * m * latency;
579 sgtc = sgtc / 3;
580 if (sgtc > 0xfffff) {
581 printk(KERN_WARNING PFX "SGTC too large %d\n", sgtc);
582 sgtc = 0xfffff;
584 return sgtc;
587 static unsigned int powernow_get(unsigned int cpu)
589 union msr_fidvidstatus fidvidstatus;
590 unsigned int cfid;
592 if (cpu)
593 return 0;
594 rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
595 cfid = fidvidstatus.bits.CFID;
597 return fsb * fid_codes[cfid] / 10;
601 static int __cpuinit acer_cpufreq_pst(const struct dmi_system_id *d)
603 printk(KERN_WARNING PFX
604 "%s laptop with broken PST tables in BIOS detected.\n",
605 d->ident);
606 printk(KERN_WARNING PFX
607 "You need to downgrade to 3A21 (09/09/2002), or try a newer "
608 "BIOS than 3A71 (01/20/2003)\n");
609 printk(KERN_WARNING PFX
610 "cpufreq scaling has been disabled as a result of this.\n");
611 return 0;
615 * Some Athlon laptops have really fucked PST tables.
616 * A BIOS update is all that can save them.
617 * Mention this, and disable cpufreq.
619 static struct dmi_system_id __cpuinitdata powernow_dmi_table[] = {
621 .callback = acer_cpufreq_pst,
622 .ident = "Acer Aspire",
623 .matches = {
624 DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"),
625 DMI_MATCH(DMI_BIOS_VERSION, "3A71"),
631 static int __cpuinit powernow_cpu_init(struct cpufreq_policy *policy)
633 union msr_fidvidstatus fidvidstatus;
634 int result;
636 if (policy->cpu != 0)
637 return -ENODEV;
639 rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
641 recalibrate_cpu_khz();
643 fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID];
644 if (!fsb) {
645 printk(KERN_WARNING PFX "can not determine bus frequency\n");
646 return -EINVAL;
648 pr_debug("FSB: %3dMHz\n", fsb/1000);
650 if (dmi_check_system(powernow_dmi_table) || acpi_force) {
651 printk(KERN_INFO PFX "PSB/PST known to be broken. "
652 "Trying ACPI instead\n");
653 result = powernow_acpi_init();
654 } else {
655 result = powernow_decode_bios(fidvidstatus.bits.MFID,
656 fidvidstatus.bits.SVID);
657 if (result) {
658 printk(KERN_INFO PFX "Trying ACPI perflib\n");
659 maximum_speed = 0;
660 minimum_speed = -1;
661 latency = 0;
662 result = powernow_acpi_init();
663 if (result) {
664 printk(KERN_INFO PFX
665 "ACPI and legacy methods failed\n");
667 } else {
668 /* SGTC use the bus clock as timer */
669 latency = fixup_sgtc();
670 printk(KERN_INFO PFX "SGTC: %d\n", latency);
674 if (result)
675 return result;
677 printk(KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n",
678 minimum_speed/1000, maximum_speed/1000);
680 policy->cpuinfo.transition_latency =
681 cpufreq_scale(2000000UL, fsb, latency);
683 policy->cur = powernow_get(0);
685 cpufreq_frequency_table_get_attr(powernow_table, policy->cpu);
687 return cpufreq_frequency_table_cpuinfo(policy, powernow_table);
690 static int powernow_cpu_exit(struct cpufreq_policy *policy)
692 cpufreq_frequency_table_put_attr(policy->cpu);
694 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
695 if (acpi_processor_perf) {
696 acpi_processor_unregister_performance(acpi_processor_perf, 0);
697 free_cpumask_var(acpi_processor_perf->shared_cpu_map);
698 kfree(acpi_processor_perf);
700 #endif
702 kfree(powernow_table);
703 return 0;
706 static struct freq_attr *powernow_table_attr[] = {
707 &cpufreq_freq_attr_scaling_available_freqs,
708 NULL,
711 static struct cpufreq_driver powernow_driver = {
712 .verify = powernow_verify,
713 .target = powernow_target,
714 .get = powernow_get,
715 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
716 .bios_limit = acpi_processor_get_bios_limit,
717 #endif
718 .init = powernow_cpu_init,
719 .exit = powernow_cpu_exit,
720 .name = "powernow-k7",
721 .owner = THIS_MODULE,
722 .attr = powernow_table_attr,
725 static int __init powernow_init(void)
727 if (check_powernow() == 0)
728 return -ENODEV;
729 return cpufreq_register_driver(&powernow_driver);
733 static void __exit powernow_exit(void)
735 cpufreq_unregister_driver(&powernow_driver);
738 module_param(acpi_force, int, 0444);
739 MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");
741 MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
742 MODULE_DESCRIPTION("Powernow driver for AMD K7 processors.");
743 MODULE_LICENSE("GPL");
745 late_initcall(powernow_init);
746 module_exit(powernow_exit);