2 * AMD K7 Powernow driver.
3 * (C) 2003 Dave Jones on behalf of SuSE Labs.
5 * Licensed under the terms of the GNU GPL License version 2.
6 * Based upon datasheets & sample CPUs kindly provided by AMD.
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.
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.
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>
27 #include <asm/timer.h> /* Needed for recalibrate_cpu_khz() */
29 #include <asm/cpu_device_id.h>
31 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
32 #include <linux/acpi.h>
33 #include <acpi/processor.h>
36 #include "powernow-k7.h"
38 #define PFX "powernow: "
58 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
59 union powernow_acpi_control_t {
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,
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,
86 /* This parameter is used in order to force ACPI instead of legacy method for
87 * configuration purpose.
90 static int acpi_force;
92 static struct cpufreq_frequency_table *powernow_table;
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;
103 static int check_fsb(unsigned int fsbspeed)
106 unsigned int f = fsb / 1000;
108 delta = (fsbspeed > f) ? fsbspeed - f : f - fsbspeed;
112 static const struct x86_cpu_id powernow_k7_cpuids[] = {
113 { X86_VENDOR_AMD, 6, },
116 MODULE_DEVICE_TABLE(x86cpu, powernow_k7_cpuids);
118 static int check_powernow(void)
120 struct cpuinfo_x86 *c = &cpu_data(0);
121 unsigned int maxei, eax, ebx, ecx, edx;
123 if (!x86_match_cpu(powernow_k7_cpuids))
126 /* Get maximum capabilities */
127 maxei = cpuid_eax(0x80000000);
128 if (maxei < 0x80000007) { /* Any powernow info ? */
130 pr_info(PFX "No powernow capabilities detected\n");
135 if ((c->x86_model == 6) && (c->x86_mask == 0)) {
136 pr_info(PFX "K7 660[A0] core detected, enabling errata workarounds\n");
140 cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
142 /* Check we can actually do something before we say anything.*/
143 if (!(edx & (1 << 1 | 1 << 2)))
146 pr_info(PFX "PowerNOW! Technology present. Can scale: ");
149 pr_cont("frequency");
153 if ((edx & (1 << 1 | 1 << 2)) == 0x6)
165 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
166 static void invalidate_entry(unsigned int entry)
168 powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
172 static int get_ranges(unsigned char *pst)
178 powernow_table = kzalloc((sizeof(*powernow_table) *
179 (number_scales + 1)), GFP_KERNEL);
183 for (j = 0 ; j < number_scales; j++) {
186 powernow_table[j].frequency = (fsb * fid_codes[fid]) / 10;
187 powernow_table[j].driver_data = fid; /* lower 8 bits */
189 speed = powernow_table[j].frequency;
191 if ((fid_codes[fid] % 10) == 5) {
192 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
198 if (speed < minimum_speed)
199 minimum_speed = speed;
200 if (speed > maximum_speed)
201 maximum_speed = speed;
204 powernow_table[j].driver_data |= (vid << 8); /* upper 8 bits */
206 pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) "
207 "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
208 fid_codes[fid] % 10, speed/1000, vid,
209 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].driver_data = 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 int powernow_target(struct cpufreq_policy *policy, 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].driver_data & 0xFF;
262 vid = (powernow_table[index].driver_data & 0xFF00) >> 8;
264 rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
265 cfid = fidvidstatus.bits.CFID;
266 freqs.old = fsb * fid_codes[cfid] / 10;
268 freqs.new = powernow_table[index].frequency;
270 /* Now do the magic poking into the MSRs. */
272 if (have_a0 == 1) /* A0 errata 5 */
275 if (freqs.old > freqs.new) {
276 /* Going down, so change FID first */
280 /* Going up, so change VID first */
293 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
295 static struct acpi_processor_performance *acpi_processor_perf;
297 static int powernow_acpi_init(void)
301 union powernow_acpi_control_t pc;
303 if (acpi_processor_perf != NULL && powernow_table != NULL) {
308 acpi_processor_perf = kzalloc(sizeof(*acpi_processor_perf), GFP_KERNEL);
309 if (!acpi_processor_perf) {
314 if (!zalloc_cpumask_var(&acpi_processor_perf->shared_cpu_map,
320 if (acpi_processor_register_performance(acpi_processor_perf, 0)) {
325 if (acpi_processor_perf->control_register.space_id !=
326 ACPI_ADR_SPACE_FIXED_HARDWARE) {
331 if (acpi_processor_perf->status_register.space_id !=
332 ACPI_ADR_SPACE_FIXED_HARDWARE) {
337 number_scales = acpi_processor_perf->state_count;
339 if (number_scales < 2) {
344 powernow_table = kzalloc((sizeof(*powernow_table) *
345 (number_scales + 1)), GFP_KERNEL);
346 if (!powernow_table) {
351 pc.val = (unsigned long) acpi_processor_perf->states[0].control;
352 for (i = 0; i < number_scales; i++) {
354 struct acpi_processor_px *state =
355 &acpi_processor_perf->states[i];
356 unsigned int speed, speed_mhz;
358 pc.val = (unsigned long) state->control;
359 pr_debug("acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
361 (u32) state->core_frequency,
363 (u32) state->transition_latency,
364 (u32) state->control,
370 powernow_table[i].frequency = fsb * fid_codes[fid] / 10;
371 powernow_table[i].driver_data = fid; /* lower 8 bits */
372 powernow_table[i].driver_data |= (vid << 8); /* upper 8 bits */
374 speed = powernow_table[i].frequency;
375 speed_mhz = speed / 1000;
377 /* processor_perflib will multiply the MHz value by 1000 to
378 * get a KHz value (e.g. 1266000). However, powernow-k7 works
379 * with true KHz values (e.g. 1266768). To ensure that all
380 * powernow frequencies are available, we must ensure that
381 * ACPI doesn't restrict them, so we round up the MHz value
382 * to ensure that perflib's computed KHz value is greater than
383 * or equal to powernow's KHz value.
385 if (speed % 1000 > 0)
388 if ((fid_codes[fid] % 10) == 5) {
393 pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) "
394 "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
395 fid_codes[fid] % 10, speed_mhz, vid,
396 mobile_vid_table[vid]/1000,
397 mobile_vid_table[vid]%1000);
399 if (state->core_frequency != speed_mhz) {
400 state->core_frequency = speed_mhz;
401 pr_debug(" Corrected ACPI frequency to %d\n",
405 if (latency < pc.bits.sgtc)
406 latency = pc.bits.sgtc;
408 if (speed < minimum_speed)
409 minimum_speed = speed;
410 if (speed > maximum_speed)
411 maximum_speed = speed;
414 powernow_table[i].frequency = CPUFREQ_TABLE_END;
415 powernow_table[i].driver_data = 0;
417 /* notify BIOS that we exist */
418 acpi_processor_notify_smm(THIS_MODULE);
423 acpi_processor_unregister_performance(0);
425 free_cpumask_var(acpi_processor_perf->shared_cpu_map);
427 kfree(acpi_processor_perf);
429 pr_warn(PFX "ACPI perflib can not be used on this platform\n");
430 acpi_processor_perf = NULL;
434 static int powernow_acpi_init(void)
436 pr_info(PFX "no support for ACPI processor found - please recompile your kernel with ACPI processor\n");
441 static void print_pst_entry(struct pst_s *pst, unsigned int j)
443 pr_debug("PST:%d (@%p)\n", j, pst);
444 pr_debug(" cpuid: 0x%x fsb: %d maxFID: 0x%x startvid: 0x%x\n",
445 pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid);
448 static int powernow_decode_bios(int maxfid, int startvid)
457 etuple = cpuid_eax(0x80000001);
459 for (i = 0xC0000; i < 0xffff0 ; i += 16) {
463 if (memcmp(p, "AMDK7PNOW!", 10) == 0) {
464 pr_debug("Found PSB header at %p\n", p);
465 psb = (struct psb_s *) p;
466 pr_debug("Table version: 0x%x\n", psb->tableversion);
467 if (psb->tableversion != 0x12) {
468 pr_info(PFX "Sorry, only v1.2 tables supported right now\n");
472 pr_debug("Flags: 0x%x\n", psb->flags);
473 if ((psb->flags & 1) == 0)
474 pr_debug("Mobile voltage regulator\n");
476 pr_debug("Desktop voltage regulator\n");
478 latency = psb->settlingtime;
480 pr_info(PFX "BIOS set settling time to %d microseconds. Should be at least 100. Correcting.\n",
484 pr_debug("Settling Time: %d microseconds.\n",
486 pr_debug("Has %d PST tables. (Only dumping ones "
487 "relevant to this CPU).\n",
492 pst = (struct pst_s *) p;
494 for (j = 0; j < psb->numpst; j++) {
495 pst = (struct pst_s *) p;
496 number_scales = pst->numpstates;
498 if ((etuple == pst->cpuid) &&
499 check_fsb(pst->fsbspeed) &&
500 (maxfid == pst->maxfid) &&
501 (startvid == pst->startvid)) {
502 print_pst_entry(pst, j);
503 p = (char *)pst + sizeof(*pst);
508 p = (char *)pst + sizeof(*pst);
509 for (k = 0; k < number_scales; k++)
513 pr_info(PFX "No PST tables match this cpuid (0x%x)\n",
515 pr_info(PFX "This is indicative of a broken BIOS\n");
527 * We use the fact that the bus frequency is somehow
528 * a multiple of 100000/3 khz, then we compute sgtc according
530 * That way, we match more how AMD thinks all of that work.
531 * We will then get the same kind of behaviour already tested under
532 * the "well-known" other OS.
534 static int fixup_sgtc(void)
545 sgtc = 100 * m * latency;
547 if (sgtc > 0xfffff) {
548 pr_warn(PFX "SGTC too large %d\n", sgtc);
554 static unsigned int powernow_get(unsigned int cpu)
556 union msr_fidvidstatus fidvidstatus;
561 rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
562 cfid = fidvidstatus.bits.CFID;
564 return fsb * fid_codes[cfid] / 10;
568 static int acer_cpufreq_pst(const struct dmi_system_id *d)
570 pr_warn(PFX "%s laptop with broken PST tables in BIOS detected\n",
572 pr_warn(PFX "You need to downgrade to 3A21 (09/09/2002), or try a newer BIOS than 3A71 (01/20/2003)\n");
573 pr_warn(PFX "cpufreq scaling has been disabled as a result of this\n");
578 * Some Athlon laptops have really fucked PST tables.
579 * A BIOS update is all that can save them.
580 * Mention this, and disable cpufreq.
582 static struct dmi_system_id powernow_dmi_table[] = {
584 .callback = acer_cpufreq_pst,
585 .ident = "Acer Aspire",
587 DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"),
588 DMI_MATCH(DMI_BIOS_VERSION, "3A71"),
594 static int powernow_cpu_init(struct cpufreq_policy *policy)
596 union msr_fidvidstatus fidvidstatus;
599 if (policy->cpu != 0)
602 rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
604 recalibrate_cpu_khz();
606 fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID];
608 pr_warn(PFX "can not determine bus frequency\n");
611 pr_debug("FSB: %3dMHz\n", fsb/1000);
613 if (dmi_check_system(powernow_dmi_table) || acpi_force) {
614 pr_info(PFX "PSB/PST known to be broken - trying ACPI instead\n");
615 result = powernow_acpi_init();
617 result = powernow_decode_bios(fidvidstatus.bits.MFID,
618 fidvidstatus.bits.SVID);
620 pr_info(PFX "Trying ACPI perflib\n");
624 result = powernow_acpi_init();
626 pr_info(PFX "ACPI and legacy methods failed\n");
629 /* SGTC use the bus clock as timer */
630 latency = fixup_sgtc();
631 pr_info(PFX "SGTC: %d\n", latency);
638 pr_info(PFX "Minimum speed %d MHz - Maximum speed %d MHz\n",
639 minimum_speed/1000, maximum_speed/1000);
641 policy->cpuinfo.transition_latency =
642 cpufreq_scale(2000000UL, fsb, latency);
644 return cpufreq_table_validate_and_show(policy, powernow_table);
647 static int powernow_cpu_exit(struct cpufreq_policy *policy)
649 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
650 if (acpi_processor_perf) {
651 acpi_processor_unregister_performance(0);
652 free_cpumask_var(acpi_processor_perf->shared_cpu_map);
653 kfree(acpi_processor_perf);
657 kfree(powernow_table);
661 static struct cpufreq_driver powernow_driver = {
662 .verify = cpufreq_generic_frequency_table_verify,
663 .target_index = powernow_target,
665 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
666 .bios_limit = acpi_processor_get_bios_limit,
668 .init = powernow_cpu_init,
669 .exit = powernow_cpu_exit,
670 .name = "powernow-k7",
671 .attr = cpufreq_generic_attr,
674 static int __init powernow_init(void)
676 if (check_powernow() == 0)
678 return cpufreq_register_driver(&powernow_driver);
682 static void __exit powernow_exit(void)
684 cpufreq_unregister_driver(&powernow_driver);
687 module_param(acpi_force, int, 0444);
688 MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");
690 MODULE_AUTHOR("Dave Jones");
691 MODULE_DESCRIPTION("Powernow driver for AMD K7 processors.");
692 MODULE_LICENSE("GPL");
694 late_initcall(powernow_init);
695 module_exit(powernow_exit);