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.
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.
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>
28 #include <asm/timer.h> /* Needed for recalibrate_cpu_khz() */
30 #include <asm/cpu_device_id.h>
32 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
33 #include <linux/acpi.h>
34 #include <acpi/processor.h>
37 #include "powernow-k7.h"
39 #define PFX "powernow: "
59 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
60 union powernow_acpi_control_t {
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;
104 static int check_fsb(unsigned int fsbspeed)
107 unsigned int f = fsb / 1000;
109 delta = (fsbspeed > f) ? fsbspeed - f : f - fsbspeed;
113 static const struct x86_cpu_id powernow_k7_cpuids[] = {
114 { X86_VENDOR_AMD, 6, },
117 MODULE_DEVICE_TABLE(x86cpu, powernow_k7_cpuids);
119 static int check_powernow(void)
121 struct cpuinfo_x86 *c = &cpu_data(0);
122 unsigned int maxei, eax, ebx, ecx, edx;
124 if (!x86_match_cpu(powernow_k7_cpuids))
127 /* Get maximum capabilities */
128 maxei = cpuid_eax(0x80000000);
129 if (maxei < 0x80000007) { /* Any powernow info ? */
131 printk(KERN_INFO PFX "No powernow capabilities detected\n");
136 if ((c->x86_model == 6) && (c->x86_mask == 0)) {
137 printk(KERN_INFO PFX "K7 660[A0] core detected, "
138 "enabling errata workarounds\n");
142 cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
144 /* Check we can actually do something before we say anything.*/
145 if (!(edx & (1 << 1 | 1 << 2)))
148 printk(KERN_INFO PFX "PowerNOW! Technology present. Can scale: ");
155 if ((edx & (1 << 1 | 1 << 2)) == 0x6)
167 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
168 static void invalidate_entry(unsigned int entry)
170 powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
174 static int get_ranges(unsigned char *pst)
180 powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) *
181 (number_scales + 1)), GFP_KERNEL);
185 for (j = 0 ; j < number_scales; j++) {
188 powernow_table[j].frequency = (fsb * fid_codes[fid]) / 10;
189 powernow_table[j].index = fid; /* lower 8 bits */
191 speed = powernow_table[j].frequency;
193 if ((fid_codes[fid] % 10) == 5) {
194 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
200 if (speed < minimum_speed)
201 minimum_speed = speed;
202 if (speed > maximum_speed)
203 maximum_speed = speed;
206 powernow_table[j].index |= (vid << 8); /* upper 8 bits */
208 pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) "
209 "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
210 fid_codes[fid] % 10, speed/1000, vid,
211 mobile_vid_table[vid]/1000,
212 mobile_vid_table[vid]%1000);
214 powernow_table[number_scales].frequency = CPUFREQ_TABLE_END;
215 powernow_table[number_scales].index = 0;
221 static void change_FID(int fid)
223 union msr_fidvidctl fidvidctl;
225 rdmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
226 if (fidvidctl.bits.FID != fid) {
227 fidvidctl.bits.SGTC = latency;
228 fidvidctl.bits.FID = fid;
229 fidvidctl.bits.VIDC = 0;
230 fidvidctl.bits.FIDC = 1;
231 wrmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
236 static void change_VID(int vid)
238 union msr_fidvidctl fidvidctl;
240 rdmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
241 if (fidvidctl.bits.VID != vid) {
242 fidvidctl.bits.SGTC = latency;
243 fidvidctl.bits.VID = vid;
244 fidvidctl.bits.FIDC = 0;
245 fidvidctl.bits.VIDC = 1;
246 wrmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
251 static void change_speed(struct cpufreq_policy *policy, unsigned int index)
254 struct cpufreq_freqs freqs;
255 union msr_fidvidstatus fidvidstatus;
258 /* fid are the lower 8 bits of the index we stored into
259 * the cpufreq frequency table in powernow_decode_bios,
260 * vid are the upper 8 bits.
263 fid = powernow_table[index].index & 0xFF;
264 vid = (powernow_table[index].index & 0xFF00) >> 8;
266 rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
267 cfid = fidvidstatus.bits.CFID;
268 freqs.old = fsb * fid_codes[cfid] / 10;
270 freqs.new = powernow_table[index].frequency;
272 cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
274 /* Now do the magic poking into the MSRs. */
276 if (have_a0 == 1) /* A0 errata 5 */
279 if (freqs.old > freqs.new) {
280 /* Going down, so change FID first */
284 /* Going up, so change VID first */
293 cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
297 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
299 static struct acpi_processor_performance *acpi_processor_perf;
301 static int powernow_acpi_init(void)
305 union powernow_acpi_control_t pc;
307 if (acpi_processor_perf != NULL && powernow_table != NULL) {
312 acpi_processor_perf = kzalloc(sizeof(struct acpi_processor_performance),
314 if (!acpi_processor_perf) {
319 if (!zalloc_cpumask_var(&acpi_processor_perf->shared_cpu_map,
325 if (acpi_processor_register_performance(acpi_processor_perf, 0)) {
330 if (acpi_processor_perf->control_register.space_id !=
331 ACPI_ADR_SPACE_FIXED_HARDWARE) {
336 if (acpi_processor_perf->status_register.space_id !=
337 ACPI_ADR_SPACE_FIXED_HARDWARE) {
342 number_scales = acpi_processor_perf->state_count;
344 if (number_scales < 2) {
349 powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) *
350 (number_scales + 1)), GFP_KERNEL);
351 if (!powernow_table) {
356 pc.val = (unsigned long) acpi_processor_perf->states[0].control;
357 for (i = 0; i < number_scales; i++) {
359 struct acpi_processor_px *state =
360 &acpi_processor_perf->states[i];
361 unsigned int speed, speed_mhz;
363 pc.val = (unsigned long) state->control;
364 pr_debug("acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
366 (u32) state->core_frequency,
368 (u32) state->transition_latency,
369 (u32) state->control,
375 powernow_table[i].frequency = fsb * fid_codes[fid] / 10;
376 powernow_table[i].index = fid; /* lower 8 bits */
377 powernow_table[i].index |= (vid << 8); /* upper 8 bits */
379 speed = powernow_table[i].frequency;
380 speed_mhz = speed / 1000;
382 /* processor_perflib will multiply the MHz value by 1000 to
383 * get a KHz value (e.g. 1266000). However, powernow-k7 works
384 * with true KHz values (e.g. 1266768). To ensure that all
385 * powernow frequencies are available, we must ensure that
386 * ACPI doesn't restrict them, so we round up the MHz value
387 * to ensure that perflib's computed KHz value is greater than
388 * or equal to powernow's KHz value.
390 if (speed % 1000 > 0)
393 if ((fid_codes[fid] % 10) == 5) {
398 pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) "
399 "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
400 fid_codes[fid] % 10, speed_mhz, vid,
401 mobile_vid_table[vid]/1000,
402 mobile_vid_table[vid]%1000);
404 if (state->core_frequency != speed_mhz) {
405 state->core_frequency = speed_mhz;
406 pr_debug(" Corrected ACPI frequency to %d\n",
410 if (latency < pc.bits.sgtc)
411 latency = pc.bits.sgtc;
413 if (speed < minimum_speed)
414 minimum_speed = speed;
415 if (speed > maximum_speed)
416 maximum_speed = speed;
419 powernow_table[i].frequency = CPUFREQ_TABLE_END;
420 powernow_table[i].index = 0;
422 /* notify BIOS that we exist */
423 acpi_processor_notify_smm(THIS_MODULE);
428 acpi_processor_unregister_performance(acpi_processor_perf, 0);
430 free_cpumask_var(acpi_processor_perf->shared_cpu_map);
432 kfree(acpi_processor_perf);
434 printk(KERN_WARNING PFX "ACPI perflib can not be used on "
436 acpi_processor_perf = NULL;
440 static int powernow_acpi_init(void)
442 printk(KERN_INFO PFX "no support for ACPI processor found."
443 " Please recompile your kernel with ACPI processor\n");
448 static void print_pst_entry(struct pst_s *pst, unsigned int j)
450 pr_debug("PST:%d (@%p)\n", j, pst);
451 pr_debug(" cpuid: 0x%x fsb: %d maxFID: 0x%x startvid: 0x%x\n",
452 pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid);
455 static int powernow_decode_bios(int maxfid, int startvid)
464 etuple = cpuid_eax(0x80000001);
466 for (i = 0xC0000; i < 0xffff0 ; i += 16) {
470 if (memcmp(p, "AMDK7PNOW!", 10) == 0) {
471 pr_debug("Found PSB header at %p\n", p);
472 psb = (struct psb_s *) p;
473 pr_debug("Table version: 0x%x\n", psb->tableversion);
474 if (psb->tableversion != 0x12) {
475 printk(KERN_INFO PFX "Sorry, only v1.2 tables"
476 " supported right now\n");
480 pr_debug("Flags: 0x%x\n", psb->flags);
481 if ((psb->flags & 1) == 0)
482 pr_debug("Mobile voltage regulator\n");
484 pr_debug("Desktop voltage regulator\n");
486 latency = psb->settlingtime;
488 printk(KERN_INFO PFX "BIOS set settling time "
489 "to %d microseconds. "
490 "Should be at least 100. "
491 "Correcting.\n", latency);
494 pr_debug("Settling Time: %d microseconds.\n",
496 pr_debug("Has %d PST tables. (Only dumping ones "
497 "relevant to this CPU).\n",
500 p += sizeof(struct psb_s);
502 pst = (struct pst_s *) p;
504 for (j = 0; j < psb->numpst; j++) {
505 pst = (struct pst_s *) p;
506 number_scales = pst->numpstates;
508 if ((etuple == pst->cpuid) &&
509 check_fsb(pst->fsbspeed) &&
510 (maxfid == pst->maxfid) &&
511 (startvid == pst->startvid)) {
512 print_pst_entry(pst, j);
513 p = (char *)pst + sizeof(struct pst_s);
518 p = (char *)pst + sizeof(struct pst_s);
519 for (k = 0; k < number_scales; k++)
523 printk(KERN_INFO PFX "No PST tables match this cpuid "
525 printk(KERN_INFO PFX "This is indicative of a broken "
537 static int powernow_target(struct cpufreq_policy *policy,
538 unsigned int target_freq,
539 unsigned int relation)
541 unsigned int newstate;
543 if (cpufreq_frequency_table_target(policy, powernow_table, target_freq,
544 relation, &newstate))
547 change_speed(policy, newstate);
553 static int powernow_verify(struct cpufreq_policy *policy)
555 return cpufreq_frequency_table_verify(policy, powernow_table);
559 * We use the fact that the bus frequency is somehow
560 * a multiple of 100000/3 khz, then we compute sgtc according
562 * That way, we match more how AMD thinks all of that work.
563 * We will then get the same kind of behaviour already tested under
564 * the "well-known" other OS.
566 static int __cpuinit fixup_sgtc(void)
577 sgtc = 100 * m * latency;
579 if (sgtc > 0xfffff) {
580 printk(KERN_WARNING PFX "SGTC too large %d\n", sgtc);
586 static unsigned int powernow_get(unsigned int cpu)
588 union msr_fidvidstatus fidvidstatus;
593 rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
594 cfid = fidvidstatus.bits.CFID;
596 return fsb * fid_codes[cfid] / 10;
600 static int __cpuinit acer_cpufreq_pst(const struct dmi_system_id *d)
602 printk(KERN_WARNING PFX
603 "%s laptop with broken PST tables in BIOS detected.\n",
605 printk(KERN_WARNING PFX
606 "You need to downgrade to 3A21 (09/09/2002), or try a newer "
607 "BIOS than 3A71 (01/20/2003)\n");
608 printk(KERN_WARNING PFX
609 "cpufreq scaling has been disabled as a result of this.\n");
614 * Some Athlon laptops have really fucked PST tables.
615 * A BIOS update is all that can save them.
616 * Mention this, and disable cpufreq.
618 static struct dmi_system_id __cpuinitdata powernow_dmi_table[] = {
620 .callback = acer_cpufreq_pst,
621 .ident = "Acer Aspire",
623 DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"),
624 DMI_MATCH(DMI_BIOS_VERSION, "3A71"),
630 static int __cpuinit powernow_cpu_init(struct cpufreq_policy *policy)
632 union msr_fidvidstatus fidvidstatus;
635 if (policy->cpu != 0)
638 rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
640 recalibrate_cpu_khz();
642 fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID];
644 printk(KERN_WARNING PFX "can not determine bus frequency\n");
647 pr_debug("FSB: %3dMHz\n", fsb/1000);
649 if (dmi_check_system(powernow_dmi_table) || acpi_force) {
650 printk(KERN_INFO PFX "PSB/PST known to be broken. "
651 "Trying ACPI instead\n");
652 result = powernow_acpi_init();
654 result = powernow_decode_bios(fidvidstatus.bits.MFID,
655 fidvidstatus.bits.SVID);
657 printk(KERN_INFO PFX "Trying ACPI perflib\n");
661 result = powernow_acpi_init();
664 "ACPI and legacy methods failed\n");
667 /* SGTC use the bus clock as timer */
668 latency = fixup_sgtc();
669 printk(KERN_INFO PFX "SGTC: %d\n", latency);
676 printk(KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n",
677 minimum_speed/1000, maximum_speed/1000);
679 policy->cpuinfo.transition_latency =
680 cpufreq_scale(2000000UL, fsb, latency);
682 policy->cur = powernow_get(0);
684 cpufreq_frequency_table_get_attr(powernow_table, policy->cpu);
686 return cpufreq_frequency_table_cpuinfo(policy, powernow_table);
689 static int powernow_cpu_exit(struct cpufreq_policy *policy)
691 cpufreq_frequency_table_put_attr(policy->cpu);
693 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
694 if (acpi_processor_perf) {
695 acpi_processor_unregister_performance(acpi_processor_perf, 0);
696 free_cpumask_var(acpi_processor_perf->shared_cpu_map);
697 kfree(acpi_processor_perf);
701 kfree(powernow_table);
705 static struct freq_attr *powernow_table_attr[] = {
706 &cpufreq_freq_attr_scaling_available_freqs,
710 static struct cpufreq_driver powernow_driver = {
711 .verify = powernow_verify,
712 .target = powernow_target,
714 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
715 .bios_limit = acpi_processor_get_bios_limit,
717 .init = powernow_cpu_init,
718 .exit = powernow_cpu_exit,
719 .name = "powernow-k7",
720 .owner = THIS_MODULE,
721 .attr = powernow_table_attr,
724 static int __init powernow_init(void)
726 if (check_powernow() == 0)
728 return cpufreq_register_driver(&powernow_driver);
732 static void __exit powernow_exit(void)
734 cpufreq_unregister_driver(&powernow_driver);
737 module_param(acpi_force, int, 0444);
738 MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");
740 MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
741 MODULE_DESCRIPTION("Powernow driver for AMD K7 processors.");
742 MODULE_LICENSE("GPL");
744 late_initcall(powernow_init);
745 module_exit(powernow_exit);