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>
6 * Licensed under the terms of the GNU GPL License version 2.
7 * Based upon datasheets & sample CPUs kindly provided by AMD.
9 * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
11 * Errata 5: Processor may fail to execute a FID/VID change in presence of interrupt.
12 * - We cli/sti on stepping A0 CPUs around the FID/VID transition.
13 * Errata 15: Processors 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/config.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/moduleparam.h>
21 #include <linux/init.h>
22 #include <linux/cpufreq.h>
23 #include <linux/slab.h>
24 #include <linux/string.h>
25 #include <linux/dmi.h>
28 #include <asm/timex.h>
30 #include <asm/system.h>
32 #if defined(CONFIG_ACPI_PROCESSOR) || defined(CONFIG_ACPI_PROCESSOR_MODULE)
33 #include <linux/acpi.h>
34 #include <acpi/processor.h>
37 #include "powernow-k7.h"
42 #define dprintk(msg...) printk(msg)
44 #define dprintk(msg...) do { } while(0)
47 #define PFX "powernow: "
67 #if defined(CONFIG_ACPI_PROCESSOR) || defined(CONFIG_ACPI_PROCESSOR_MODULE)
68 union powernow_acpi_control_t {
79 /* divide by 1000 to get VID. */
80 static int mobile_vid_table[32] = {
81 2000, 1950, 1900, 1850, 1800, 1750, 1700, 1650,
82 1600, 1550, 1500, 1450, 1400, 1350, 1300, 0,
83 1275, 1250, 1225, 1200, 1175, 1150, 1125, 1100,
84 1075, 1050, 1024, 1000, 975, 950, 925, 0,
87 /* divide by 10 to get FID. */
88 static int fid_codes[32] = {
89 110, 115, 120, 125, 50, 55, 60, 65,
90 70, 75, 80, 85, 90, 95, 100, 105,
91 30, 190, 40, 200, 130, 135, 140, 210,
92 150, 225, 160, 165, 170, 180, -1, -1,
95 /* This parameter is used in order to force ACPI instead of legacy method for
96 * configuration purpose.
99 static int acpi_force;
101 static struct cpufreq_frequency_table *powernow_table;
103 static unsigned int can_scale_bus;
104 static unsigned int can_scale_vid;
105 static unsigned int minimum_speed=-1;
106 static unsigned int maximum_speed;
107 static unsigned int number_scales;
108 static unsigned int fsb;
109 static unsigned int latency;
112 static int check_fsb(unsigned int fsbspeed)
115 unsigned int f = fsb / 1000;
117 delta = (fsbspeed > f) ? fsbspeed - f : f - fsbspeed;
121 static int check_powernow(void)
123 struct cpuinfo_x86 *c = cpu_data;
124 unsigned int maxei, eax, ebx, ecx, edx;
126 if ((c->x86_vendor != X86_VENDOR_AMD) || (c->x86 !=6)) {
128 printk (KERN_INFO PFX "This module only works with AMD K7 CPUs\n");
133 /* Get maximum capabilities */
134 maxei = cpuid_eax (0x80000000);
135 if (maxei < 0x80000007) { /* Any powernow info ? */
137 printk (KERN_INFO PFX "No powernow capabilities detected\n");
142 if ((c->x86_model == 6) && (c->x86_mask == 0)) {
143 printk (KERN_INFO PFX "K7 660[A0] core detected, enabling errata workarounds\n");
147 cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
149 /* Check we can actually do something before we say anything.*/
150 if (!(edx & (1 << 1 | 1 << 2)))
153 printk (KERN_INFO PFX "PowerNOW! Technology present. Can scale: ");
156 printk ("frequency");
160 if ((edx & (1 << 1 | 1 << 2)) == 0x6)
173 static int get_ranges (unsigned char *pst)
179 powernow_table = kmalloc((sizeof(struct cpufreq_frequency_table) * (number_scales + 1)), GFP_KERNEL);
182 memset(powernow_table, 0, (sizeof(struct cpufreq_frequency_table) * (number_scales + 1)));
184 for (j=0 ; j < number_scales; j++) {
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 #if defined(CONFIG_ACPI_PROCESSOR) || defined(CONFIG_ACPI_PROCESSOR_MODULE)
195 powernow_table[j].frequency = CPUFREQ_ENTRY_INVALID;
199 dprintk (KERN_INFO PFX " FID: 0x%x (%d.%dx [%dMHz])\t", fid,
200 fid_codes[fid] / 10, fid_codes[fid] % 10, speed/1000);
202 if (speed < minimum_speed)
203 minimum_speed = speed;
204 if (speed > maximum_speed)
205 maximum_speed = speed;
208 powernow_table[j].index |= (vid << 8); /* upper 8 bits */
209 dprintk ("VID: 0x%x (%d.%03dV)\n", vid, mobile_vid_table[vid]/1000,
210 mobile_vid_table[vid]%1000);
212 powernow_table[number_scales].frequency = CPUFREQ_TABLE_END;
213 powernow_table[number_scales].index = 0;
219 static void change_FID(int fid)
221 union msr_fidvidctl fidvidctl;
223 rdmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val);
224 if (fidvidctl.bits.FID != fid) {
225 fidvidctl.bits.SGTC = latency;
226 fidvidctl.bits.FID = fid;
227 fidvidctl.bits.VIDC = 0;
228 fidvidctl.bits.FIDC = 1;
229 wrmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val);
234 static void change_VID(int vid)
236 union msr_fidvidctl fidvidctl;
238 rdmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val);
239 if (fidvidctl.bits.VID != vid) {
240 fidvidctl.bits.SGTC = latency;
241 fidvidctl.bits.VID = vid;
242 fidvidctl.bits.FIDC = 0;
243 fidvidctl.bits.VIDC = 1;
244 wrmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val);
249 static void change_speed (unsigned int index)
252 struct cpufreq_freqs freqs;
253 union msr_fidvidstatus fidvidstatus;
256 /* fid are the lower 8 bits of the index we stored into
257 * the cpufreq frequency table in powernow_decode_bios,
258 * vid are the upper 8 bits.
261 fid = powernow_table[index].index & 0xFF;
262 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(&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(&freqs, CPUFREQ_POSTCHANGE);
297 #if defined(CONFIG_ACPI_PROCESSOR) || defined(CONFIG_ACPI_PROCESSOR_MODULE)
299 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 = kmalloc(sizeof(struct acpi_processor_performance),
315 if (!acpi_processor_perf) {
320 memset(acpi_processor_perf, 0, sizeof(struct acpi_processor_performance));
322 if (acpi_processor_register_performance(acpi_processor_perf, 0)) {
327 if (acpi_processor_perf->control_register.space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) {
332 if (acpi_processor_perf->status_register.space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) {
337 number_scales = acpi_processor_perf->state_count;
339 if (number_scales < 2) {
344 powernow_table = kmalloc((number_scales + 1) * (sizeof(struct cpufreq_frequency_table)), GFP_KERNEL);
345 if (!powernow_table) {
350 memset(powernow_table, 0, ((number_scales + 1) * sizeof(struct cpufreq_frequency_table)));
352 pc.val = (unsigned long) acpi_processor_perf->states[0].control;
353 for (i = 0; i < number_scales; i++) {
357 pc.val = (unsigned long) acpi_processor_perf->states[i].control;
358 dprintk (KERN_INFO PFX "acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
360 (u32) acpi_processor_perf->states[i].core_frequency,
361 (u32) acpi_processor_perf->states[i].power,
362 (u32) acpi_processor_perf->states[i].transition_latency,
363 (u32) acpi_processor_perf->states[i].control,
369 powernow_table[i].frequency = fsb * fid_codes[fid] / 10;
370 powernow_table[i].index = fid; /* lower 8 bits */
371 powernow_table[i].index |= (vid << 8); /* upper 8 bits */
373 speed = powernow_table[i].frequency;
375 if ((fid_codes[fid] % 10)==5) {
377 powernow_table[i].frequency = CPUFREQ_ENTRY_INVALID;
380 dprintk (KERN_INFO PFX " FID: 0x%x (%d.%dx [%dMHz])\t", fid,
381 fid_codes[fid] / 10, fid_codes[fid] % 10, speed/1000);
382 dprintk ("VID: 0x%x (%d.%03dV)\n", vid, mobile_vid_table[vid]/1000,
383 mobile_vid_table[vid]%1000);
385 if (latency < pc.bits.sgtc)
386 latency = pc.bits.sgtc;
388 if (speed < minimum_speed)
389 minimum_speed = speed;
390 if (speed > maximum_speed)
391 maximum_speed = speed;
394 powernow_table[i].frequency = CPUFREQ_TABLE_END;
395 powernow_table[i].index = 0;
400 acpi_processor_unregister_performance(acpi_processor_perf, 0);
402 kfree(acpi_processor_perf);
404 printk(KERN_WARNING PFX "ACPI perflib can not be used in this platform\n");
405 acpi_processor_perf = NULL;
409 static int powernow_acpi_init(void)
411 printk(KERN_INFO PFX "no support for ACPI processor found."
412 " Please recompile your kernel with ACPI processor\n");
417 static int powernow_decode_bios (int maxfid, int startvid)
426 etuple = cpuid_eax(0x80000001);
428 for (i=0xC0000; i < 0xffff0 ; i+=16) {
432 if (memcmp(p, "AMDK7PNOW!", 10) == 0){
433 dprintk (KERN_INFO PFX "Found PSB header at %p\n", p);
434 psb = (struct psb_s *) p;
435 dprintk (KERN_INFO PFX "Table version: 0x%x\n", psb->tableversion);
436 if (psb->tableversion != 0x12) {
437 printk (KERN_INFO PFX "Sorry, only v1.2 tables supported right now\n");
441 dprintk (KERN_INFO PFX "Flags: 0x%x (", psb->flags);
442 if ((psb->flags & 1)==0) {
447 dprintk (" voltage regulator)\n");
449 latency = psb->settlingtime;
451 printk (KERN_INFO PFX "BIOS set settling time to %d microseconds."
452 "Should be at least 100. Correcting.\n", latency);
455 dprintk (KERN_INFO PFX "Settling Time: %d microseconds.\n", psb->settlingtime);
456 dprintk (KERN_INFO PFX "Has %d PST tables. (Only dumping ones relevant to this CPU).\n", psb->numpst);
458 p += sizeof (struct psb_s);
460 pst = (struct pst_s *) p;
462 for (i = 0 ; i <psb->numpst; i++) {
463 pst = (struct pst_s *) p;
464 number_scales = pst->numpstates;
466 if ((etuple == pst->cpuid) && check_fsb(pst->fsbspeed) &&
467 (maxfid==pst->maxfid) && (startvid==pst->startvid))
469 dprintk (KERN_INFO PFX "PST:%d (@%p)\n", i, pst);
470 dprintk (KERN_INFO PFX " cpuid: 0x%x\t", pst->cpuid);
471 dprintk ("fsb: %d\t", pst->fsbspeed);
472 dprintk ("maxFID: 0x%x\t", pst->maxfid);
473 dprintk ("startvid: 0x%x\n", pst->startvid);
475 ret = get_ranges ((char *) pst + sizeof (struct pst_s));
479 p = (char *) pst + sizeof (struct pst_s);
480 for (j=0 ; j < number_scales; j++)
484 printk (KERN_INFO PFX "No PST tables match this cpuid (0x%x)\n", etuple);
485 printk (KERN_INFO PFX "This is indicative of a broken BIOS.\n");
496 static int powernow_target (struct cpufreq_policy *policy,
497 unsigned int target_freq,
498 unsigned int relation)
500 unsigned int newstate;
502 if (cpufreq_frequency_table_target(policy, powernow_table, target_freq, relation, &newstate))
505 change_speed(newstate);
511 static int powernow_verify (struct cpufreq_policy *policy)
513 return cpufreq_frequency_table_verify(policy, powernow_table);
517 * We use the fact that the bus frequency is somehow
518 * a multiple of 100000/3 khz, then we compute sgtc according
520 * That way, we match more how AMD thinks all of that work.
521 * We will then get the same kind of behaviour already tested under
522 * the "well-known" other OS.
524 static int __init fixup_sgtc(void)
535 sgtc = 100 * m * latency;
537 if (sgtc > 0xfffff) {
538 printk(KERN_WARNING PFX "SGTC too large %d\n", sgtc);
544 static unsigned int powernow_get(unsigned int cpu)
546 union msr_fidvidstatus fidvidstatus;
551 rdmsrl (MSR_K7_FID_VID_STATUS, fidvidstatus.val);
552 cfid = fidvidstatus.bits.CFID;
554 return (fsb * fid_codes[cfid] / 10);
558 static int __init acer_cpufreq_pst(struct dmi_system_id *d)
560 printk(KERN_WARNING "%s laptop with broken PST tables in BIOS detected.\n", d->ident);
561 printk(KERN_WARNING "You need to downgrade to 3A21 (09/09/2002), or try a newer BIOS than 3A71 (01/20/2003)\n");
562 printk(KERN_WARNING "cpufreq scaling has been disabled as a result of this.\n");
567 * Some Athlon laptops have really fucked PST tables.
568 * A BIOS update is all that can save them.
569 * Mention this, and disable cpufreq.
571 static struct dmi_system_id __initdata powernow_dmi_table[] = {
573 .callback = acer_cpufreq_pst,
574 .ident = "Acer Aspire",
576 DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"),
577 DMI_MATCH(DMI_BIOS_VERSION, "3A71"),
583 static int __init powernow_cpu_init (struct cpufreq_policy *policy)
585 union msr_fidvidstatus fidvidstatus;
588 if (policy->cpu != 0)
591 rdmsrl (MSR_K7_FID_VID_STATUS, fidvidstatus.val);
593 /* A K7 with powernow technology is set to max frequency by BIOS */
594 fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID];
596 printk(KERN_WARNING PFX "can not determine bus frequency\n");
599 dprintk(KERN_INFO PFX "FSB: %3d.%03d MHz\n", fsb/1000, fsb%1000);
601 if (dmi_check_system(powernow_dmi_table) || acpi_force) {
602 printk (KERN_INFO PFX "PSB/PST known to be broken. Trying ACPI instead\n");
603 result = powernow_acpi_init();
605 result = powernow_decode_bios(fidvidstatus.bits.MFID, fidvidstatus.bits.SVID);
607 printk (KERN_INFO PFX "Trying ACPI perflib\n");
611 result = powernow_acpi_init();
613 printk (KERN_INFO PFX "ACPI and legacy methods failed\n");
614 printk (KERN_INFO PFX "See http://www.codemonkey.org.uk/projects/cpufreq/powernow-k7.shtml\n");
617 /* SGTC use the bus clock as timer */
618 latency = fixup_sgtc();
619 printk(KERN_INFO PFX "SGTC: %d\n", latency);
626 printk (KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n",
627 minimum_speed/1000, maximum_speed/1000);
629 policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
631 policy->cpuinfo.transition_latency = 20 * latency / fsb;
633 policy->cur = powernow_get(0);
635 cpufreq_frequency_table_get_attr(powernow_table, policy->cpu);
637 return cpufreq_frequency_table_cpuinfo(policy, powernow_table);
640 static int powernow_cpu_exit (struct cpufreq_policy *policy) {
641 cpufreq_frequency_table_put_attr(policy->cpu);
645 static struct freq_attr* powernow_table_attr[] = {
646 &cpufreq_freq_attr_scaling_available_freqs,
650 static struct cpufreq_driver powernow_driver = {
651 .verify = powernow_verify,
652 .target = powernow_target,
654 .init = powernow_cpu_init,
655 .exit = powernow_cpu_exit,
656 .name = "powernow-k7",
657 .owner = THIS_MODULE,
658 .attr = powernow_table_attr,
661 static int __init powernow_init (void)
663 if (check_powernow()==0)
665 return cpufreq_register_driver(&powernow_driver);
669 static void __exit powernow_exit (void)
671 #if defined(CONFIG_ACPI_PROCESSOR) || defined(CONFIG_ACPI_PROCESSOR_MODULE)
672 if (acpi_processor_perf) {
673 acpi_processor_unregister_performance(acpi_processor_perf, 0);
674 kfree(acpi_processor_perf);
677 cpufreq_unregister_driver(&powernow_driver);
679 kfree(powernow_table);
682 module_param(acpi_force, int, 0444);
683 MODULE_PARM_DESC(acpi_force, "Force ACPI to be used");
685 MODULE_AUTHOR ("Dave Jones <davej@codemonkey.org.uk>");
686 MODULE_DESCRIPTION ("Powernow driver for AMD K7 processors.");
687 MODULE_LICENSE ("GPL");
689 late_initcall(powernow_init);
690 module_exit(powernow_exit);