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/system.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
#ifdef CONFIG_CPU_FREQ_DEBUG
72
/* divide by 1000 to get VCore voltage in V. */
73
static const int mobile_vid_table[32] = {
74
2000, 1950, 1900, 1850, 1800, 1750, 1700, 1650,
75
1600, 1550, 1500, 1450, 1400, 1350, 1300, 0,
76
1275, 1250, 1225, 1200, 1175, 1150, 1125, 1100,
77
1075, 1050, 1025, 1000, 975, 950, 925, 0,
81
/* divide by 10 to get FID. */
82
static const int fid_codes[32] = {
83
110, 115, 120, 125, 50, 55, 60, 65,
84
70, 75, 80, 85, 90, 95, 100, 105,
85
30, 190, 40, 200, 130, 135, 140, 210,
86
150, 225, 160, 165, 170, 180, -1, -1,
89
/* This parameter is used in order to force ACPI instead of legacy method for
90
* configuration purpose.
93
static int acpi_force;
95
static struct cpufreq_frequency_table *powernow_table;
97
static unsigned int can_scale_bus;
98
static unsigned int can_scale_vid;
99
static unsigned int minimum_speed = -1;
100
static unsigned int maximum_speed;
101
static unsigned int number_scales;
102
static unsigned int fsb;
103
static unsigned int latency;
106
#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, \
109
static int check_fsb(unsigned int fsbspeed)
112
unsigned int f = fsb / 1000;
114
delta = (fsbspeed > f) ? fsbspeed - f : f - fsbspeed;
118
static int check_powernow(void)
120
struct cpuinfo_x86 *c = &cpu_data(0);
121
unsigned int maxei, eax, ebx, ecx, edx;
123
if ((c->x86_vendor != X86_VENDOR_AMD) || (c->x86 != 6)) {
125
printk(KERN_INFO PFX "This module only works with "
131
/* Get maximum capabilities */
132
maxei = cpuid_eax(0x80000000);
133
if (maxei < 0x80000007) { /* Any powernow info ? */
135
printk(KERN_INFO PFX "No powernow capabilities detected\n");
140
if ((c->x86_model == 6) && (c->x86_mask == 0)) {
141
printk(KERN_INFO PFX "K7 660[A0] core detected, "
142
"enabling errata workarounds\n");
146
cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
148
/* Check we can actually do something before we say anything.*/
149
if (!(edx & (1 << 1 | 1 << 2)))
152
printk(KERN_INFO PFX "PowerNOW! Technology present. Can scale: ");
159
if ((edx & (1 << 1 | 1 << 2)) == 0x6)
171
#ifdef CONFIG_X86_POWERNOW_K7_ACPI
172
static void invalidate_entry(unsigned int entry)
174
powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
178
static int get_ranges(unsigned char *pst)
184
powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) *
185
(number_scales + 1)), GFP_KERNEL);
189
for (j = 0 ; j < number_scales; j++) {
192
powernow_table[j].frequency = (fsb * fid_codes[fid]) / 10;
193
powernow_table[j].index = fid; /* lower 8 bits */
195
speed = powernow_table[j].frequency;
197
if ((fid_codes[fid] % 10) == 5) {
198
#ifdef CONFIG_X86_POWERNOW_K7_ACPI
204
if (speed < minimum_speed)
205
minimum_speed = speed;
206
if (speed > maximum_speed)
207
maximum_speed = speed;
210
powernow_table[j].index |= (vid << 8); /* upper 8 bits */
212
dprintk(" FID: 0x%x (%d.%dx [%dMHz]) "
213
"VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
214
fid_codes[fid] % 10, speed/1000, vid,
215
mobile_vid_table[vid]/1000,
216
mobile_vid_table[vid]%1000);
218
powernow_table[number_scales].frequency = CPUFREQ_TABLE_END;
219
powernow_table[number_scales].index = 0;
225
static void change_FID(int fid)
227
union msr_fidvidctl fidvidctl;
229
rdmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
230
if (fidvidctl.bits.FID != fid) {
231
fidvidctl.bits.SGTC = latency;
232
fidvidctl.bits.FID = fid;
233
fidvidctl.bits.VIDC = 0;
234
fidvidctl.bits.FIDC = 1;
235
wrmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
240
static void change_VID(int vid)
242
union msr_fidvidctl fidvidctl;
244
rdmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
245
if (fidvidctl.bits.VID != vid) {
246
fidvidctl.bits.SGTC = latency;
247
fidvidctl.bits.VID = vid;
248
fidvidctl.bits.FIDC = 0;
249
fidvidctl.bits.VIDC = 1;
250
wrmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
255
static void change_speed(unsigned int index)
258
struct cpufreq_freqs freqs;
259
union msr_fidvidstatus fidvidstatus;
262
/* fid are the lower 8 bits of the index we stored into
263
* the cpufreq frequency table in powernow_decode_bios,
264
* vid are the upper 8 bits.
267
fid = powernow_table[index].index & 0xFF;
268
vid = (powernow_table[index].index & 0xFF00) >> 8;
272
rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
273
cfid = fidvidstatus.bits.CFID;
274
freqs.old = fsb * fid_codes[cfid] / 10;
276
freqs.new = powernow_table[index].frequency;
278
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
280
/* Now do the magic poking into the MSRs. */
282
if (have_a0 == 1) /* A0 errata 5 */
285
if (freqs.old > freqs.new) {
286
/* Going down, so change FID first */
290
/* Going up, so change VID first */
299
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
303
#ifdef CONFIG_X86_POWERNOW_K7_ACPI
305
static struct acpi_processor_performance *acpi_processor_perf;
307
static int powernow_acpi_init(void)
311
union powernow_acpi_control_t pc;
313
if (acpi_processor_perf != NULL && powernow_table != NULL) {
318
acpi_processor_perf = kzalloc(sizeof(struct acpi_processor_performance),
320
if (!acpi_processor_perf) {
325
if (!zalloc_cpumask_var(&acpi_processor_perf->shared_cpu_map,
331
if (acpi_processor_register_performance(acpi_processor_perf, 0)) {
336
if (acpi_processor_perf->control_register.space_id !=
337
ACPI_ADR_SPACE_FIXED_HARDWARE) {
342
if (acpi_processor_perf->status_register.space_id !=
343
ACPI_ADR_SPACE_FIXED_HARDWARE) {
348
number_scales = acpi_processor_perf->state_count;
350
if (number_scales < 2) {
355
powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) *
356
(number_scales + 1)), GFP_KERNEL);
357
if (!powernow_table) {
362
pc.val = (unsigned long) acpi_processor_perf->states[0].control;
363
for (i = 0; i < number_scales; i++) {
365
struct acpi_processor_px *state =
366
&acpi_processor_perf->states[i];
367
unsigned int speed, speed_mhz;
369
pc.val = (unsigned long) state->control;
370
dprintk("acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
372
(u32) state->core_frequency,
374
(u32) state->transition_latency,
375
(u32) state->control,
381
powernow_table[i].frequency = fsb * fid_codes[fid] / 10;
382
powernow_table[i].index = fid; /* lower 8 bits */
383
powernow_table[i].index |= (vid << 8); /* upper 8 bits */
385
speed = powernow_table[i].frequency;
386
speed_mhz = speed / 1000;
388
/* processor_perflib will multiply the MHz value by 1000 to
389
* get a KHz value (e.g. 1266000). However, powernow-k7 works
390
* with true KHz values (e.g. 1266768). To ensure that all
391
* powernow frequencies are available, we must ensure that
392
* ACPI doesn't restrict them, so we round up the MHz value
393
* to ensure that perflib's computed KHz value is greater than
394
* or equal to powernow's KHz value.
396
if (speed % 1000 > 0)
399
if ((fid_codes[fid] % 10) == 5) {
404
dprintk(" FID: 0x%x (%d.%dx [%dMHz]) "
405
"VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
406
fid_codes[fid] % 10, speed_mhz, vid,
407
mobile_vid_table[vid]/1000,
408
mobile_vid_table[vid]%1000);
410
if (state->core_frequency != speed_mhz) {
411
state->core_frequency = speed_mhz;
412
dprintk(" Corrected ACPI frequency to %d\n",
416
if (latency < pc.bits.sgtc)
417
latency = pc.bits.sgtc;
419
if (speed < minimum_speed)
420
minimum_speed = speed;
421
if (speed > maximum_speed)
422
maximum_speed = speed;
425
powernow_table[i].frequency = CPUFREQ_TABLE_END;
426
powernow_table[i].index = 0;
428
/* notify BIOS that we exist */
429
acpi_processor_notify_smm(THIS_MODULE);
434
acpi_processor_unregister_performance(acpi_processor_perf, 0);
436
free_cpumask_var(acpi_processor_perf->shared_cpu_map);
438
kfree(acpi_processor_perf);
440
printk(KERN_WARNING PFX "ACPI perflib can not be used on "
442
acpi_processor_perf = NULL;
446
static int powernow_acpi_init(void)
448
printk(KERN_INFO PFX "no support for ACPI processor found."
449
" Please recompile your kernel with ACPI processor\n");
454
static void print_pst_entry(struct pst_s *pst, unsigned int j)
456
dprintk("PST:%d (@%p)\n", j, pst);
457
dprintk(" cpuid: 0x%x fsb: %d maxFID: 0x%x startvid: 0x%x\n",
458
pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid);
461
static int powernow_decode_bios(int maxfid, int startvid)
470
etuple = cpuid_eax(0x80000001);
472
for (i = 0xC0000; i < 0xffff0 ; i += 16) {
476
if (memcmp(p, "AMDK7PNOW!", 10) == 0) {
477
dprintk("Found PSB header at %p\n", p);
478
psb = (struct psb_s *) p;
479
dprintk("Table version: 0x%x\n", psb->tableversion);
480
if (psb->tableversion != 0x12) {
481
printk(KERN_INFO PFX "Sorry, only v1.2 tables"
482
" supported right now\n");
486
dprintk("Flags: 0x%x\n", psb->flags);
487
if ((psb->flags & 1) == 0)
488
dprintk("Mobile voltage regulator\n");
490
dprintk("Desktop voltage regulator\n");
492
latency = psb->settlingtime;
494
printk(KERN_INFO PFX "BIOS set settling time "
495
"to %d microseconds. "
496
"Should be at least 100. "
497
"Correcting.\n", latency);
500
dprintk("Settling Time: %d microseconds.\n",
502
dprintk("Has %d PST tables. (Only dumping ones "
503
"relevant to this CPU).\n",
506
p += sizeof(struct psb_s);
508
pst = (struct pst_s *) p;
510
for (j = 0; j < psb->numpst; j++) {
511
pst = (struct pst_s *) p;
512
number_scales = pst->numpstates;
514
if ((etuple == pst->cpuid) &&
515
check_fsb(pst->fsbspeed) &&
516
(maxfid == pst->maxfid) &&
517
(startvid == pst->startvid)) {
518
print_pst_entry(pst, j);
519
p = (char *)pst + sizeof(struct pst_s);
524
p = (char *)pst + sizeof(struct pst_s);
525
for (k = 0; k < number_scales; k++)
529
printk(KERN_INFO PFX "No PST tables match this cpuid "
531
printk(KERN_INFO PFX "This is indicative of a broken "
543
static int powernow_target(struct cpufreq_policy *policy,
544
unsigned int target_freq,
545
unsigned int relation)
547
unsigned int newstate;
549
if (cpufreq_frequency_table_target(policy, powernow_table, target_freq,
550
relation, &newstate))
553
change_speed(newstate);
559
static int powernow_verify(struct cpufreq_policy *policy)
561
return cpufreq_frequency_table_verify(policy, powernow_table);
565
* We use the fact that the bus frequency is somehow
566
* a multiple of 100000/3 khz, then we compute sgtc according
568
* That way, we match more how AMD thinks all of that work.
569
* We will then get the same kind of behaviour already tested under
570
* the "well-known" other OS.
572
static int __cpuinit fixup_sgtc(void)
583
sgtc = 100 * m * latency;
585
if (sgtc > 0xfffff) {
586
printk(KERN_WARNING PFX "SGTC too large %d\n", sgtc);
592
static unsigned int powernow_get(unsigned int cpu)
594
union msr_fidvidstatus fidvidstatus;
599
rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
600
cfid = fidvidstatus.bits.CFID;
602
return fsb * fid_codes[cfid] / 10;
606
static int __cpuinit acer_cpufreq_pst(const struct dmi_system_id *d)
608
printk(KERN_WARNING PFX
609
"%s laptop with broken PST tables in BIOS detected.\n",
611
printk(KERN_WARNING PFX
612
"You need to downgrade to 3A21 (09/09/2002), or try a newer "
613
"BIOS than 3A71 (01/20/2003)\n");
614
printk(KERN_WARNING PFX
615
"cpufreq scaling has been disabled as a result of this.\n");
620
* Some Athlon laptops have really fucked PST tables.
621
* A BIOS update is all that can save them.
622
* Mention this, and disable cpufreq.
624
static struct dmi_system_id __cpuinitdata powernow_dmi_table[] = {
626
.callback = acer_cpufreq_pst,
627
.ident = "Acer Aspire",
629
DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"),
630
DMI_MATCH(DMI_BIOS_VERSION, "3A71"),
636
static int __cpuinit powernow_cpu_init(struct cpufreq_policy *policy)
638
union msr_fidvidstatus fidvidstatus;
641
if (policy->cpu != 0)
644
rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
646
recalibrate_cpu_khz();
648
fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID];
650
printk(KERN_WARNING PFX "can not determine bus frequency\n");
653
dprintk("FSB: %3dMHz\n", fsb/1000);
655
if (dmi_check_system(powernow_dmi_table) || acpi_force) {
656
printk(KERN_INFO PFX "PSB/PST known to be broken. "
657
"Trying ACPI instead\n");
658
result = powernow_acpi_init();
660
result = powernow_decode_bios(fidvidstatus.bits.MFID,
661
fidvidstatus.bits.SVID);
663
printk(KERN_INFO PFX "Trying ACPI perflib\n");
667
result = powernow_acpi_init();
670
"ACPI and legacy methods failed\n");
673
/* SGTC use the bus clock as timer */
674
latency = fixup_sgtc();
675
printk(KERN_INFO PFX "SGTC: %d\n", latency);
682
printk(KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n",
683
minimum_speed/1000, maximum_speed/1000);
685
policy->cpuinfo.transition_latency =
686
cpufreq_scale(2000000UL, fsb, latency);
688
policy->cur = powernow_get(0);
690
cpufreq_frequency_table_get_attr(powernow_table, policy->cpu);
692
return cpufreq_frequency_table_cpuinfo(policy, powernow_table);
695
static int powernow_cpu_exit(struct cpufreq_policy *policy)
697
cpufreq_frequency_table_put_attr(policy->cpu);
699
#ifdef CONFIG_X86_POWERNOW_K7_ACPI
700
if (acpi_processor_perf) {
701
acpi_processor_unregister_performance(acpi_processor_perf, 0);
702
free_cpumask_var(acpi_processor_perf->shared_cpu_map);
703
kfree(acpi_processor_perf);
707
kfree(powernow_table);
711
static struct freq_attr *powernow_table_attr[] = {
712
&cpufreq_freq_attr_scaling_available_freqs,
716
static struct cpufreq_driver powernow_driver = {
717
.verify = powernow_verify,
718
.target = powernow_target,
720
#ifdef CONFIG_X86_POWERNOW_K7_ACPI
721
.bios_limit = acpi_processor_get_bios_limit,
723
.init = powernow_cpu_init,
724
.exit = powernow_cpu_exit,
725
.name = "powernow-k7",
726
.owner = THIS_MODULE,
727
.attr = powernow_table_attr,
730
static int __init powernow_init(void)
732
if (check_powernow() == 0)
734
return cpufreq_register_driver(&powernow_driver);
738
static void __exit powernow_exit(void)
740
cpufreq_unregister_driver(&powernow_driver);
743
module_param(acpi_force, int, 0444);
744
MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");
746
MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
747
MODULE_DESCRIPTION("Powernow driver for AMD K7 processors.");
748
MODULE_LICENSE("GPL");
750
late_initcall(powernow_init);
751
module_exit(powernow_exit);