drivers/cpufreq/powernow-k7.c

   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>
   5  *
   6  *  Licensed under the terms of the GNU GPL License version 2.
   7  *  Based upon datasheets & sample CPUs kindly provided by AMD.
   8  *
   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.
  15  */
  16
  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>
  27
  28 #include <asm/timer.h>          /* Needed for recalibrate_cpu_khz() */
  29 #include <asm/msr.h>
  30 #include <asm/system.h>
  31
  32 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
  33 #include <linux/acpi.h>
  34 #include <acpi/processor.h>
  35 #endif
  36
  37 #include "powernow-k7.h"
  38
  39 #define PFX "powernow: "
  40
  41
  42 struct psb_s {
  43         u8 signature[10];
  44         u8 tableversion;
  45         u8 flags;
  46         u16 settlingtime;
  47         u8 reserved1;
  48         u8 numpst;
  49 };
  50
  51 struct pst_s {
  52         u32 cpuid;
  53         u8 fsbspeed;
  54         u8 maxfid;
  55         u8 startvid;
  56         u8 numpstates;
  57 };
  58
  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;
  68 };
  69 #endif
  70
  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,
  77 };
  78
  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,
  85 };
  86
  87 /* This parameter is used in order to force ACPI instead of legacy method for
  88  * configuration purpose.
  89  */
  90
  91 static int acpi_force;
  92
  93 static struct cpufreq_frequency_table *powernow_table;
  94
  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;
 103
 104 static int check_fsb(unsigned int fsbspeed)
 105 {
 106         int delta;
 107         unsigned int f = fsb / 1000;
 108
 109         delta = (fsbspeed > f) ? fsbspeed - f : f - fsbspeed;
 110         return delta < 5;
 111 }
 112
 113 static int check_powernow(void)
 114 {
 115         struct cpuinfo_x86 *c = &cpu_data(0);
 116         unsigned int maxei, eax, ebx, ecx, edx;
 117
 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;
 124         }
 125
 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;
 133         }
 134
 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;
 139         }
 140
 141         cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
 142
 143         /* Check we can actually do something before we say anything.*/
 144         if (!(edx & (1 << 1 | 1 << 2)))
 145                 return 0;
 146
 147         printk(KERN_INFO PFX "PowerNOW! Technology present. Can scale: ");
 148
 149         if (edx & 1 << 1) {
 150                 printk("frequency");
 151                 can_scale_bus = 1;
 152         }
 153
 154         if ((edx & (1 << 1 | 1 << 2)) == 0x6)
 155                 printk(" and ");
 156
 157         if (edx & 1 << 2) {
 158                 printk("voltage");
 159                 can_scale_vid = 1;
 160         }
 161
 162         printk(".\n");
 163         return 1;
 164 }
 165
 166 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
 167 static void invalidate_entry(unsigned int entry)
 168 {
 169         powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
 170 }
 171 #endif
 172
 173 static int get_ranges(unsigned char *pst)
 174 {
 175         unsigned int j;
 176         unsigned int speed;
 177         u8 fid, vid;
 178
 179         powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) *
 180                                 (number_scales + 1)), GFP_KERNEL);
 181         if (!powernow_table)
 182                 return -ENOMEM;
 183
 184         for (j = 0 ; j < number_scales; j++) {
 185                 fid = *pst++;
 186
 187                 powernow_table[j].frequency = (fsb * fid_codes[fid]) / 10;
 188                 powernow_table[j].index = fid; /* lower 8 bits */
 189
 190                 speed = powernow_table[j].frequency;
 191
 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
 197                 }
 198
 199                 if (speed < minimum_speed)
 200                         minimum_speed = speed;
 201                 if (speed > maximum_speed)
 202                         maximum_speed = speed;
 203
 204                 vid = *pst++;
 205                 powernow_table[j].index |= (vid << 8); /* upper 8 bits */
 206
 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);
 212         }
 213         powernow_table[number_scales].frequency = CPUFREQ_TABLE_END;
 214         powernow_table[number_scales].index = 0;
 215
 216         return 0;
 217 }
 218
 219
 220 static void change_FID(int fid)
 221 {
 222         union msr_fidvidctl fidvidctl;
 223
 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);
 231         }
 232 }
 233
 234
 235 static void change_VID(int vid)
 236 {
 237         union msr_fidvidctl fidvidctl;
 238
 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);
 246         }
 247 }
 248
 249
 250 static void change_speed(unsigned int index)
 251 {
 252         u8 fid, vid;
 253         struct cpufreq_freqs freqs;
 254         union msr_fidvidstatus fidvidstatus;
 255         int cfid;
 256
 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.
 260          */
 261
 262         fid = powernow_table[index].index & 0xFF;
 263         vid = (powernow_table[index].index & 0xFF00) >> 8;
 264
 265         freqs.cpu = 0;
 266
 267         rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
 268         cfid = fidvidstatus.bits.CFID;
 269         freqs.old = fsb * fid_codes[cfid] / 10;
 270
 271         freqs.new = powernow_table[index].frequency;
 272
 273         cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 274
 275         /* Now do the magic poking into the MSRs.  */
 276
 277         if (have_a0 == 1)       /* A0 errata 5 */
 278                 local_irq_disable();
 279
 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);
 288         }
 289
 290
 291         if (have_a0 == 1)
 292                 local_irq_enable();
 293
 294         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 295 }
 296
 297
 298 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
 299
 300 static struct acpi_processor_performance *acpi_processor_perf;
 301
 302 static int powernow_acpi_init(void)
 303 {
 304         int i;
 305         int retval = 0;
 306         union powernow_acpi_control_t pc;
 307
 308         if (acpi_processor_perf != NULL && powernow_table != NULL) {
 309                 retval = -EINVAL;
 310                 goto err0;
 311         }
 312
 313         acpi_processor_perf = kzalloc(sizeof(struct acpi_processor_performance),
 314                                       GFP_KERNEL);
 315         if (!acpi_processor_perf) {
 316                 retval = -ENOMEM;
 317                 goto err0;
 318         }
 319
 320         if (!zalloc_cpumask_var(&acpi_processor_perf->shared_cpu_map,
 321                                                                 GFP_KERNEL)) {
 322                 retval = -ENOMEM;
 323                 goto err05;
 324         }
 325
 326         if (acpi_processor_register_performance(acpi_processor_perf, 0)) {
 327                 retval = -EIO;
 328                 goto err1;
 329         }
 330
 331         if (acpi_processor_perf->control_register.space_id !=
 332                         ACPI_ADR_SPACE_FIXED_HARDWARE) {
 333                 retval = -ENODEV;
 334                 goto err2;
 335         }
 336
 337         if (acpi_processor_perf->status_register.space_id !=
 338                         ACPI_ADR_SPACE_FIXED_HARDWARE) {
 339                 retval = -ENODEV;
 340                 goto err2;
 341         }
 342
 343         number_scales = acpi_processor_perf->state_count;
 344
 345         if (number_scales < 2) {
 346                 retval = -ENODEV;
 347                 goto err2;
 348         }
 349
 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;
 355         }
 356
 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;
 363
 364                 pc.val = (unsigned long) state->control;
 365                 pr_debug("acpi:  P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
 366                          i,
 367                          (u32) state->core_frequency,
 368                          (u32) state->power,
 369                          (u32) state->transition_latency,
 370                          (u32) state->control,
 371                          pc.bits.sgtc);
 372
 373                 vid = pc.bits.vid;
 374                 fid = pc.bits.fid;
 375
 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 */
 379
 380                 speed = powernow_table[i].frequency;
 381                 speed_mhz = speed / 1000;
 382
 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.
 390                  */
 391                 if (speed % 1000 > 0)
 392                         speed_mhz++;
 393
 394                 if ((fid_codes[fid] % 10) == 5) {
 395                         if (have_a0 == 1)
 396                                 invalidate_entry(i);
 397                 }
 398
 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);
 404
 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);
 409                 }
 410
 411                 if (latency < pc.bits.sgtc)
 412                         latency = pc.bits.sgtc;
 413
 414                 if (speed < minimum_speed)
 415                         minimum_speed = speed;
 416                 if (speed > maximum_speed)
 417                         maximum_speed = speed;
 418         }
 419
 420         powernow_table[i].frequency = CPUFREQ_TABLE_END;
 421         powernow_table[i].index = 0;
 422
 423         /* notify BIOS that we exist */
 424         acpi_processor_notify_smm(THIS_MODULE);
 425
 426         return 0;
 427
 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;
 439 }
 440 #else
 441 static int powernow_acpi_init(void)
 442 {
 443         printk(KERN_INFO PFX "no support for ACPI processor found."
 444                "  Please recompile your kernel with ACPI processor\n");
 445         return -EINVAL;
 446 }
 447 #endif
 448
 449 static void print_pst_entry(struct pst_s *pst, unsigned int j)
 450 {
 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);
 454 }
 455
 456 static int powernow_decode_bios(int maxfid, int startvid)
 457 {
 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;
 464
 465         etuple = cpuid_eax(0x80000001);
 466
 467         for (i = 0xC0000; i < 0xffff0 ; i += 16) {
 468
 469                 p = phys_to_virt(i);
 470
 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;
 479                         }
 480
 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");
 486
 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;
 494                         }
 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);
 500
 501                         p += sizeof(struct psb_s);
 502
 503                         pst = (struct pst_s *) p;
 504
 505                         for (j = 0; j < psb->numpst; j++) {
 506                                 pst = (struct pst_s *) p;
 507                                 number_scales = pst->numpstates;
 508
 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;
 522                                 }
 523                         }
 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");
 528
 529                         return -EINVAL;
 530                 }
 531                 p++;
 532         }
 533
 534         return -ENODEV;
 535 }
 536
 537
 538 static int powernow_target(struct cpufreq_policy *policy,
 539                             unsigned int target_freq,
 540                             unsigned int relation)
 541 {
 542         unsigned int newstate;
 543
 544         if (cpufreq_frequency_table_target(policy, powernow_table, target_freq,
 545                                 relation, &newstate))
 546                 return -EINVAL;
 547
 548         change_speed(newstate);
 549
 550         return 0;
 551 }
 552
 553
 554 static int powernow_verify(struct cpufreq_policy *policy)
 555 {
 556         return cpufreq_frequency_table_verify(policy, powernow_table);
 557 }
 558
 559 /*
 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.
 566  */
 567 static int __cpuinit fixup_sgtc(void)
 568 {
 569         unsigned int sgtc;
 570         unsigned int m;
 571
 572         m = fsb / 3333;
 573         if ((m % 10) >= 5)
 574                 m += 5;
 575
 576         m /= 10;
 577
 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;
 583         }
 584         return sgtc;
 585 }
 586
 587 static unsigned int powernow_get(unsigned int cpu)
 588 {
 589         union msr_fidvidstatus fidvidstatus;
 590         unsigned int cfid;
 591
 592         if (cpu)
 593                 return 0;
 594         rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
 595         cfid = fidvidstatus.bits.CFID;
 596
 597         return fsb * fid_codes[cfid] / 10;
 598 }
 599
 600
 601 static int __cpuinit acer_cpufreq_pst(const struct dmi_system_id *d)
 602 {
 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;
 612 }
 613
 614 /*
 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.
 618  */
 619 static struct dmi_system_id __cpuinitdata powernow_dmi_table[] = {
 620         {
 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"),
 626                 },
 627         },
 628         { }
 629 };
 630
 631 static int __cpuinit powernow_cpu_init(struct cpufreq_policy *policy)
 632 {
 633         union msr_fidvidstatus fidvidstatus;
 634         int result;
 635
 636         if (policy->cpu != 0)
 637                 return -ENODEV;
 638
 639         rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
 640
 641         recalibrate_cpu_khz();
 642
 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;
 647         }
 648         pr_debug("FSB: %3dMHz\n", fsb/1000);
 649
 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");
 666                         }
 667                 } else {
 668                         /* SGTC use the bus clock as timer */
 669                         latency = fixup_sgtc();
 670                         printk(KERN_INFO PFX "SGTC: %d\n", latency);
 671                 }
 672         }
 673
 674         if (result)
 675                 return result;
 676
 677         printk(KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n",
 678                                 minimum_speed/1000, maximum_speed/1000);
 679
 680         policy->cpuinfo.transition_latency =
 681                 cpufreq_scale(2000000UL, fsb, latency);
 682
 683         policy->cur = powernow_get(0);
 684
 685         cpufreq_frequency_table_get_attr(powernow_table, policy->cpu);
 686
 687         return cpufreq_frequency_table_cpuinfo(policy, powernow_table);
 688 }
 689
 690 static int powernow_cpu_exit(struct cpufreq_policy *policy)
 691 {
 692         cpufreq_frequency_table_put_attr(policy->cpu);
 693
 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);
 699         }
 700 #endif
 701
 702         kfree(powernow_table);
 703         return 0;
 704 }
 705
 706 static struct freq_attr *powernow_table_attr[] = {
 707         &cpufreq_freq_attr_scaling_available_freqs,
 708         NULL,
 709 };
 710
 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,
 723 };
 724
 725 static int __init powernow_init(void)
 726 {
 727         if (check_powernow() == 0)
 728                 return -ENODEV;
 729         return cpufreq_register_driver(&powernow_driver);
 730 }
 731
 732
 733 static void __exit powernow_exit(void)
 734 {
 735         cpufreq_unregister_driver(&powernow_driver);
 736 }
 737
 738 module_param(acpi_force,  int, 0444);
 739 MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");
 740
 741 MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
 742 MODULE_DESCRIPTION("Powernow driver for AMD K7 processors.");
 743 MODULE_LICENSE("GPL");
 744
 745 late_initcall(powernow_init);
 746 module_exit(powernow_exit);
 747