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/cpu_device_id.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 const struct x86_cpu_id powernow_k7_cpuids[] = {
 114         { X86_VENDOR_AMD, 6, },
 115         {}
 116 };
 117 MODULE_DEVICE_TABLE(x86cpu, powernow_k7_cpuids);
 118
 119 static int check_powernow(void)
 120 {
 121         struct cpuinfo_x86 *c = &cpu_data(0);
 122         unsigned int maxei, eax, ebx, ecx, edx;
 123
 124         if (!x86_match_cpu(powernow_k7_cpuids))
 125                 return 0;
 126
 127         /* Get maximum capabilities */
 128         maxei = cpuid_eax(0x80000000);
 129         if (maxei < 0x80000007) {       /* Any powernow info ? */
 130 #ifdef MODULE
 131                 printk(KERN_INFO PFX "No powernow capabilities detected\n");
 132 #endif
 133                 return 0;
 134         }
 135
 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");
 139                 have_a0 = 1;
 140         }
 141
 142         cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
 143
 144         /* Check we can actually do something before we say anything.*/
 145         if (!(edx & (1 << 1 | 1 << 2)))
 146                 return 0;
 147
 148         printk(KERN_INFO PFX "PowerNOW! Technology present. Can scale: ");
 149
 150         if (edx & 1 << 1) {
 151                 printk("frequency");
 152                 can_scale_bus = 1;
 153         }
 154
 155         if ((edx & (1 << 1 | 1 << 2)) == 0x6)
 156                 printk(" and ");
 157
 158         if (edx & 1 << 2) {
 159                 printk("voltage");
 160                 can_scale_vid = 1;
 161         }
 162
 163         printk(".\n");
 164         return 1;
 165 }
 166
 167 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
 168 static void invalidate_entry(unsigned int entry)
 169 {
 170         powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
 171 }
 172 #endif
 173
 174 static int get_ranges(unsigned char *pst)
 175 {
 176         unsigned int j;
 177         unsigned int speed;
 178         u8 fid, vid;
 179
 180         powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) *
 181                                 (number_scales + 1)), GFP_KERNEL);
 182         if (!powernow_table)
 183                 return -ENOMEM;
 184
 185         for (j = 0 ; j < number_scales; j++) {
 186                 fid = *pst++;
 187
 188                 powernow_table[j].frequency = (fsb * fid_codes[fid]) / 10;
 189                 powernow_table[j].index = fid; /* lower 8 bits */
 190
 191                 speed = powernow_table[j].frequency;
 192
 193                 if ((fid_codes[fid] % 10) == 5) {
 194 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
 195                         if (have_a0 == 1)
 196                                 invalidate_entry(j);
 197 #endif
 198                 }
 199
 200                 if (speed < minimum_speed)
 201                         minimum_speed = speed;
 202                 if (speed > maximum_speed)
 203                         maximum_speed = speed;
 204
 205                 vid = *pst++;
 206                 powernow_table[j].index |= (vid << 8); /* upper 8 bits */
 207
 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);
 213         }
 214         powernow_table[number_scales].frequency = CPUFREQ_TABLE_END;
 215         powernow_table[number_scales].index = 0;
 216
 217         return 0;
 218 }
 219
 220
 221 static void change_FID(int fid)
 222 {
 223         union msr_fidvidctl fidvidctl;
 224
 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);
 232         }
 233 }
 234
 235
 236 static void change_VID(int vid)
 237 {
 238         union msr_fidvidctl fidvidctl;
 239
 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);
 247         }
 248 }
 249
 250
 251 static void change_speed(struct cpufreq_policy *policy, unsigned int index)
 252 {
 253         u8 fid, vid;
 254         struct cpufreq_freqs freqs;
 255         union msr_fidvidstatus fidvidstatus;
 256         int cfid;
 257
 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.
 261          */
 262
 263         fid = powernow_table[index].index & 0xFF;
 264         vid = (powernow_table[index].index & 0xFF00) >> 8;
 265
 266         rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
 267         cfid = fidvidstatus.bits.CFID;
 268         freqs.old = fsb * fid_codes[cfid] / 10;
 269
 270         freqs.new = powernow_table[index].frequency;
 271
 272         cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
 273
 274         /* Now do the magic poking into the MSRs.  */
 275
 276         if (have_a0 == 1)       /* A0 errata 5 */
 277                 local_irq_disable();
 278
 279         if (freqs.old > freqs.new) {
 280                 /* Going down, so change FID first */
 281                 change_FID(fid);
 282                 change_VID(vid);
 283         } else {
 284                 /* Going up, so change VID first */
 285                 change_VID(vid);
 286                 change_FID(fid);
 287         }
 288
 289
 290         if (have_a0 == 1)
 291                 local_irq_enable();
 292
 293         cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
 294 }
 295
 296
 297 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
 298
 299 static struct acpi_processor_performance *acpi_processor_perf;
 300
 301 static int powernow_acpi_init(void)
 302 {
 303         int i;
 304         int retval = 0;
 305         union powernow_acpi_control_t pc;
 306
 307         if (acpi_processor_perf != NULL && powernow_table != NULL) {
 308                 retval = -EINVAL;
 309                 goto err0;
 310         }
 311
 312         acpi_processor_perf = kzalloc(sizeof(struct acpi_processor_performance),
 313                                       GFP_KERNEL);
 314         if (!acpi_processor_perf) {
 315                 retval = -ENOMEM;
 316                 goto err0;
 317         }
 318
 319         if (!zalloc_cpumask_var(&acpi_processor_perf->shared_cpu_map,
 320                                                                 GFP_KERNEL)) {
 321                 retval = -ENOMEM;
 322                 goto err05;
 323         }
 324
 325         if (acpi_processor_register_performance(acpi_processor_perf, 0)) {
 326                 retval = -EIO;
 327                 goto err1;
 328         }
 329
 330         if (acpi_processor_perf->control_register.space_id !=
 331                         ACPI_ADR_SPACE_FIXED_HARDWARE) {
 332                 retval = -ENODEV;
 333                 goto err2;
 334         }
 335
 336         if (acpi_processor_perf->status_register.space_id !=
 337                         ACPI_ADR_SPACE_FIXED_HARDWARE) {
 338                 retval = -ENODEV;
 339                 goto err2;
 340         }
 341
 342         number_scales = acpi_processor_perf->state_count;
 343
 344         if (number_scales < 2) {
 345                 retval = -ENODEV;
 346                 goto err2;
 347         }
 348
 349         powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) *
 350                                 (number_scales + 1)), GFP_KERNEL);
 351         if (!powernow_table) {
 352                 retval = -ENOMEM;
 353                 goto err2;
 354         }
 355
 356         pc.val = (unsigned long) acpi_processor_perf->states[0].control;
 357         for (i = 0; i < number_scales; i++) {
 358                 u8 fid, vid;
 359                 struct acpi_processor_px *state =
 360                         &acpi_processor_perf->states[i];
 361                 unsigned int speed, speed_mhz;
 362
 363                 pc.val = (unsigned long) state->control;
 364                 pr_debug("acpi:  P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
 365                          i,
 366                          (u32) state->core_frequency,
 367                          (u32) state->power,
 368                          (u32) state->transition_latency,
 369                          (u32) state->control,
 370                          pc.bits.sgtc);
 371
 372                 vid = pc.bits.vid;
 373                 fid = pc.bits.fid;
 374
 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 */
 378
 379                 speed = powernow_table[i].frequency;
 380                 speed_mhz = speed / 1000;
 381
 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.
 389                  */
 390                 if (speed % 1000 > 0)
 391                         speed_mhz++;
 392
 393                 if ((fid_codes[fid] % 10) == 5) {
 394                         if (have_a0 == 1)
 395                                 invalidate_entry(i);
 396                 }
 397
 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);
 403
 404                 if (state->core_frequency != speed_mhz) {
 405                         state->core_frequency = speed_mhz;
 406                         pr_debug("   Corrected ACPI frequency to %d\n",
 407                                 speed_mhz);
 408                 }
 409
 410                 if (latency < pc.bits.sgtc)
 411                         latency = pc.bits.sgtc;
 412
 413                 if (speed < minimum_speed)
 414                         minimum_speed = speed;
 415                 if (speed > maximum_speed)
 416                         maximum_speed = speed;
 417         }
 418
 419         powernow_table[i].frequency = CPUFREQ_TABLE_END;
 420         powernow_table[i].index = 0;
 421
 422         /* notify BIOS that we exist */
 423         acpi_processor_notify_smm(THIS_MODULE);
 424
 425         return 0;
 426
 427 err2:
 428         acpi_processor_unregister_performance(acpi_processor_perf, 0);
 429 err1:
 430         free_cpumask_var(acpi_processor_perf->shared_cpu_map);
 431 err05:
 432         kfree(acpi_processor_perf);
 433 err0:
 434         printk(KERN_WARNING PFX "ACPI perflib can not be used on "
 435                         "this platform\n");
 436         acpi_processor_perf = NULL;
 437         return retval;
 438 }
 439 #else
 440 static int powernow_acpi_init(void)
 441 {
 442         printk(KERN_INFO PFX "no support for ACPI processor found."
 443                "  Please recompile your kernel with ACPI processor\n");
 444         return -EINVAL;
 445 }
 446 #endif
 447
 448 static void print_pst_entry(struct pst_s *pst, unsigned int j)
 449 {
 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);
 453 }
 454
 455 static int powernow_decode_bios(int maxfid, int startvid)
 456 {
 457         struct psb_s *psb;
 458         struct pst_s *pst;
 459         unsigned int i, j;
 460         unsigned char *p;
 461         unsigned int etuple;
 462         unsigned int ret;
 463
 464         etuple = cpuid_eax(0x80000001);
 465
 466         for (i = 0xC0000; i < 0xffff0 ; i += 16) {
 467
 468                 p = phys_to_virt(i);
 469
 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");
 477                                 return -ENODEV;
 478                         }
 479
 480                         pr_debug("Flags: 0x%x\n", psb->flags);
 481                         if ((psb->flags & 1) == 0)
 482                                 pr_debug("Mobile voltage regulator\n");
 483                         else
 484                                 pr_debug("Desktop voltage regulator\n");
 485
 486                         latency = psb->settlingtime;
 487                         if (latency < 100) {
 488                                 printk(KERN_INFO PFX "BIOS set settling time "
 489                                                 "to %d microseconds. "
 490                                                 "Should be at least 100. "
 491                                                 "Correcting.\n", latency);
 492                                 latency = 100;
 493                         }
 494                         pr_debug("Settling Time: %d microseconds.\n",
 495                                         psb->settlingtime);
 496                         pr_debug("Has %d PST tables. (Only dumping ones "
 497                                         "relevant to this CPU).\n",
 498                                         psb->numpst);
 499
 500                         p += sizeof(struct psb_s);
 501
 502                         pst = (struct pst_s *) p;
 503
 504                         for (j = 0; j < psb->numpst; j++) {
 505                                 pst = (struct pst_s *) p;
 506                                 number_scales = pst->numpstates;
 507
 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);
 514                                         ret = get_ranges(p);
 515                                         return ret;
 516                                 } else {
 517                                         unsigned int k;
 518                                         p = (char *)pst + sizeof(struct pst_s);
 519                                         for (k = 0; k < number_scales; k++)
 520                                                 p += 2;
 521                                 }
 522                         }
 523                         printk(KERN_INFO PFX "No PST tables match this cpuid "
 524                                         "(0x%x)\n", etuple);
 525                         printk(KERN_INFO PFX "This is indicative of a broken "
 526                                         "BIOS.\n");
 527
 528                         return -EINVAL;
 529                 }
 530                 p++;
 531         }
 532
 533         return -ENODEV;
 534 }
 535
 536
 537 static int powernow_target(struct cpufreq_policy *policy,
 538                             unsigned int target_freq,
 539                             unsigned int relation)
 540 {
 541         unsigned int newstate;
 542
 543         if (cpufreq_frequency_table_target(policy, powernow_table, target_freq,
 544                                 relation, &newstate))
 545                 return -EINVAL;
 546
 547         change_speed(policy, newstate);
 548
 549         return 0;
 550 }
 551
 552
 553 static int powernow_verify(struct cpufreq_policy *policy)
 554 {
 555         return cpufreq_frequency_table_verify(policy, powernow_table);
 556 }
 557
 558 /*
 559  * We use the fact that the bus frequency is somehow
 560  * a multiple of 100000/3 khz, then we compute sgtc according
 561  * to this multiple.
 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.
 565  */
 566 static int __cpuinit fixup_sgtc(void)
 567 {
 568         unsigned int sgtc;
 569         unsigned int m;
 570
 571         m = fsb / 3333;
 572         if ((m % 10) >= 5)
 573                 m += 5;
 574
 575         m /= 10;
 576
 577         sgtc = 100 * m * latency;
 578         sgtc = sgtc / 3;
 579         if (sgtc > 0xfffff) {
 580                 printk(KERN_WARNING PFX "SGTC too large %d\n", sgtc);
 581                 sgtc = 0xfffff;
 582         }
 583         return sgtc;
 584 }
 585
 586 static unsigned int powernow_get(unsigned int cpu)
 587 {
 588         union msr_fidvidstatus fidvidstatus;
 589         unsigned int cfid;
 590
 591         if (cpu)
 592                 return 0;
 593         rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
 594         cfid = fidvidstatus.bits.CFID;
 595
 596         return fsb * fid_codes[cfid] / 10;
 597 }
 598
 599
 600 static int __cpuinit acer_cpufreq_pst(const struct dmi_system_id *d)
 601 {
 602         printk(KERN_WARNING PFX
 603                 "%s laptop with broken PST tables in BIOS detected.\n",
 604                 d->ident);
 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");
 610         return 0;
 611 }
 612
 613 /*
 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.
 617  */
 618 static struct dmi_system_id __cpuinitdata powernow_dmi_table[] = {
 619         {
 620                 .callback = acer_cpufreq_pst,
 621                 .ident = "Acer Aspire",
 622                 .matches = {
 623                         DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"),
 624                         DMI_MATCH(DMI_BIOS_VERSION, "3A71"),
 625                 },
 626         },
 627         { }
 628 };
 629
 630 static int __cpuinit powernow_cpu_init(struct cpufreq_policy *policy)
 631 {
 632         union msr_fidvidstatus fidvidstatus;
 633         int result;
 634
 635         if (policy->cpu != 0)
 636                 return -ENODEV;
 637
 638         rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
 639
 640         recalibrate_cpu_khz();
 641
 642         fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID];
 643         if (!fsb) {
 644                 printk(KERN_WARNING PFX "can not determine bus frequency\n");
 645                 return -EINVAL;
 646         }
 647         pr_debug("FSB: %3dMHz\n", fsb/1000);
 648
 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();
 653         } else {
 654                 result = powernow_decode_bios(fidvidstatus.bits.MFID,
 655                                 fidvidstatus.bits.SVID);
 656                 if (result) {
 657                         printk(KERN_INFO PFX "Trying ACPI perflib\n");
 658                         maximum_speed = 0;
 659                         minimum_speed = -1;
 660                         latency = 0;
 661                         result = powernow_acpi_init();
 662                         if (result) {
 663                                 printk(KERN_INFO PFX
 664                                         "ACPI and legacy methods failed\n");
 665                         }
 666                 } else {
 667                         /* SGTC use the bus clock as timer */
 668                         latency = fixup_sgtc();
 669                         printk(KERN_INFO PFX "SGTC: %d\n", latency);
 670                 }
 671         }
 672
 673         if (result)
 674                 return result;
 675
 676         printk(KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n",
 677                                 minimum_speed/1000, maximum_speed/1000);
 678
 679         policy->cpuinfo.transition_latency =
 680                 cpufreq_scale(2000000UL, fsb, latency);
 681
 682         policy->cur = powernow_get(0);
 683
 684         cpufreq_frequency_table_get_attr(powernow_table, policy->cpu);
 685
 686         return cpufreq_frequency_table_cpuinfo(policy, powernow_table);
 687 }
 688
 689 static int powernow_cpu_exit(struct cpufreq_policy *policy)
 690 {
 691         cpufreq_frequency_table_put_attr(policy->cpu);
 692
 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);
 698         }
 699 #endif
 700
 701         kfree(powernow_table);
 702         return 0;
 703 }
 704
 705 static struct freq_attr *powernow_table_attr[] = {
 706         &cpufreq_freq_attr_scaling_available_freqs,
 707         NULL,
 708 };
 709
 710 static struct cpufreq_driver powernow_driver = {
 711         .verify         = powernow_verify,
 712         .target         = powernow_target,
 713         .get            = powernow_get,
 714 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
 715         .bios_limit     = acpi_processor_get_bios_limit,
 716 #endif
 717         .init           = powernow_cpu_init,
 718         .exit           = powernow_cpu_exit,
 719         .name           = "powernow-k7",
 720         .owner          = THIS_MODULE,
 721         .attr           = powernow_table_attr,
 722 };
 723
 724 static int __init powernow_init(void)
 725 {
 726         if (check_powernow() == 0)
 727                 return -ENODEV;
 728         return cpufreq_register_driver(&powernow_driver);
 729 }
 730
 731
 732 static void __exit powernow_exit(void)
 733 {
 734         cpufreq_unregister_driver(&powernow_driver);
 735 }
 736
 737 module_param(acpi_force,  int, 0444);
 738 MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");
 739
 740 MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
 741 MODULE_DESCRIPTION("Powernow driver for AMD K7 processors.");
 742 MODULE_LICENSE("GPL");
 743
 744 late_initcall(powernow_init);
 745 module_exit(powernow_exit);
 746