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 #include <asm/cpu_device_id.h>
  32
  33 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
  34 #include <linux/acpi.h>
  35 #include <acpi/processor.h>
  36 #endif
  37
  38 #include "powernow-k7.h"
  39
  40 #define PFX "powernow: "
  41
  42
  43 struct psb_s {
  44         u8 signature[10];
  45         u8 tableversion;
  46         u8 flags;
  47         u16 settlingtime;
  48         u8 reserved1;
  49         u8 numpst;
  50 };
  51
  52 struct pst_s {
  53         u32 cpuid;
  54         u8 fsbspeed;
  55         u8 maxfid;
  56         u8 startvid;
  57         u8 numpstates;
  58 };
  59
  60 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
  61 union powernow_acpi_control_t {
  62         struct {
  63                 unsigned long fid:5,
  64                         vid:5,
  65                         sgtc:20,
  66                         res1:2;
  67         } bits;
  68         unsigned long val;
  69 };
  70 #endif
  71
  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,
  78 };
  79
  80 /* divide by 10 to get FID. */
  81 static const int fid_codes[32] = {
  82     110, 115, 120, 125, 50, 55, 60, 65,
  83     70, 75, 80, 85, 90, 95, 100, 105,
  84     30, 190, 40, 200, 130, 135, 140, 210,
  85     150, 225, 160, 165, 170, 180, -1, -1,
  86 };
  87
  88 /* This parameter is used in order to force ACPI instead of legacy method for
  89  * configuration purpose.
  90  */
  91
  92 static int acpi_force;
  93
  94 static struct cpufreq_frequency_table *powernow_table;
  95
  96 static unsigned int can_scale_bus;
  97 static unsigned int can_scale_vid;
  98 static unsigned int minimum_speed = -1;
  99 static unsigned int maximum_speed;
 100 static unsigned int number_scales;
 101 static unsigned int fsb;
 102 static unsigned int latency;
 103 static char have_a0;
 104
 105 static int check_fsb(unsigned int fsbspeed)
 106 {
 107         int delta;
 108         unsigned int f = fsb / 1000;
 109
 110         delta = (fsbspeed > f) ? fsbspeed - f : f - fsbspeed;
 111         return delta < 5;
 112 }
 113
 114 static const struct x86_cpu_id powernow_k7_cpuids[] = {
 115         { X86_VENDOR_AMD, 6, },
 116         {}
 117 };
 118 MODULE_DEVICE_TABLE(x86cpu, powernow_k7_cpuids);
 119
 120 static int check_powernow(void)
 121 {
 122         struct cpuinfo_x86 *c = &cpu_data(0);
 123         unsigned int maxei, eax, ebx, ecx, edx;
 124
 125         if (!x86_match_cpu(powernow_k7_cpuids))
 126                 return 0;
 127
 128         /* Get maximum capabilities */
 129         maxei = cpuid_eax(0x80000000);
 130         if (maxei < 0x80000007) {       /* Any powernow info ? */
 131 #ifdef MODULE
 132                 printk(KERN_INFO PFX "No powernow capabilities detected\n");
 133 #endif
 134                 return 0;
 135         }
 136
 137         if ((c->x86_model == 6) && (c->x86_mask == 0)) {
 138                 printk(KERN_INFO PFX "K7 660[A0] core detected, "
 139                                 "enabling errata workarounds\n");
 140                 have_a0 = 1;
 141         }
 142
 143         cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
 144
 145         /* Check we can actually do something before we say anything.*/
 146         if (!(edx & (1 << 1 | 1 << 2)))
 147                 return 0;
 148
 149         printk(KERN_INFO PFX "PowerNOW! Technology present. Can scale: ");
 150
 151         if (edx & 1 << 1) {
 152                 printk("frequency");
 153                 can_scale_bus = 1;
 154         }
 155
 156         if ((edx & (1 << 1 | 1 << 2)) == 0x6)
 157                 printk(" and ");
 158
 159         if (edx & 1 << 2) {
 160                 printk("voltage");
 161                 can_scale_vid = 1;
 162         }
 163
 164         printk(".\n");
 165         return 1;
 166 }
 167
 168 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
 169 static void invalidate_entry(unsigned int entry)
 170 {
 171         powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
 172 }
 173 #endif
 174
 175 static int get_ranges(unsigned char *pst)
 176 {
 177         unsigned int j;
 178         unsigned int speed;
 179         u8 fid, vid;
 180
 181         powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) *
 182                                 (number_scales + 1)), GFP_KERNEL);
 183         if (!powernow_table)
 184                 return -ENOMEM;
 185
 186         for (j = 0 ; j < number_scales; j++) {
 187                 fid = *pst++;
 188
 189                 powernow_table[j].frequency = (fsb * fid_codes[fid]) / 10;
 190                 powernow_table[j].index = fid; /* lower 8 bits */
 191
 192                 speed = powernow_table[j].frequency;
 193
 194                 if ((fid_codes[fid] % 10) == 5) {
 195 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
 196                         if (have_a0 == 1)
 197                                 invalidate_entry(j);
 198 #endif
 199                 }
 200
 201                 if (speed < minimum_speed)
 202                         minimum_speed = speed;
 203                 if (speed > maximum_speed)
 204                         maximum_speed = speed;
 205
 206                 vid = *pst++;
 207                 powernow_table[j].index |= (vid << 8); /* upper 8 bits */
 208
 209                 pr_debug("   FID: 0x%x (%d.%dx [%dMHz])  "
 210                          "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
 211                          fid_codes[fid] % 10, speed/1000, vid,
 212                          mobile_vid_table[vid]/1000,
 213                          mobile_vid_table[vid]%1000);
 214         }
 215         powernow_table[number_scales].frequency = CPUFREQ_TABLE_END;
 216         powernow_table[number_scales].index = 0;
 217
 218         return 0;
 219 }
 220
 221
 222 static void change_FID(int fid)
 223 {
 224         union msr_fidvidctl fidvidctl;
 225
 226         rdmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
 227         if (fidvidctl.bits.FID != fid) {
 228                 fidvidctl.bits.SGTC = latency;
 229                 fidvidctl.bits.FID = fid;
 230                 fidvidctl.bits.VIDC = 0;
 231                 fidvidctl.bits.FIDC = 1;
 232                 wrmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
 233         }
 234 }
 235
 236
 237 static void change_VID(int vid)
 238 {
 239         union msr_fidvidctl fidvidctl;
 240
 241         rdmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
 242         if (fidvidctl.bits.VID != vid) {
 243                 fidvidctl.bits.SGTC = latency;
 244                 fidvidctl.bits.VID = vid;
 245                 fidvidctl.bits.FIDC = 0;
 246                 fidvidctl.bits.VIDC = 1;
 247                 wrmsrl(MSR_K7_FID_VID_CTL, fidvidctl.val);
 248         }
 249 }
 250
 251
 252 static void change_speed(unsigned int index)
 253 {
 254         u8 fid, vid;
 255         struct cpufreq_freqs freqs;
 256         union msr_fidvidstatus fidvidstatus;
 257         int cfid;
 258
 259         /* fid are the lower 8 bits of the index we stored into
 260          * the cpufreq frequency table in powernow_decode_bios,
 261          * vid are the upper 8 bits.
 262          */
 263
 264         fid = powernow_table[index].index & 0xFF;
 265         vid = (powernow_table[index].index & 0xFF00) >> 8;
 266
 267         freqs.cpu = 0;
 268
 269         rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
 270         cfid = fidvidstatus.bits.CFID;
 271         freqs.old = fsb * fid_codes[cfid] / 10;
 272
 273         freqs.new = powernow_table[index].frequency;
 274
 275         cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 276
 277         /* Now do the magic poking into the MSRs.  */
 278
 279         if (have_a0 == 1)       /* A0 errata 5 */
 280                 local_irq_disable();
 281
 282         if (freqs.old > freqs.new) {
 283                 /* Going down, so change FID first */
 284                 change_FID(fid);
 285                 change_VID(vid);
 286         } else {
 287                 /* Going up, so change VID first */
 288                 change_VID(vid);
 289                 change_FID(fid);
 290         }
 291
 292
 293         if (have_a0 == 1)
 294                 local_irq_enable();
 295
 296         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 297 }
 298
 299
 300 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
 301
 302 static struct acpi_processor_performance *acpi_processor_perf;
 303
 304 static int powernow_acpi_init(void)
 305 {
 306         int i;
 307         int retval = 0;
 308         union powernow_acpi_control_t pc;
 309
 310         if (acpi_processor_perf != NULL && powernow_table != NULL) {
 311                 retval = -EINVAL;
 312                 goto err0;
 313         }
 314
 315         acpi_processor_perf = kzalloc(sizeof(struct acpi_processor_performance),
 316                                       GFP_KERNEL);
 317         if (!acpi_processor_perf) {
 318                 retval = -ENOMEM;
 319                 goto err0;
 320         }
 321
 322         if (!zalloc_cpumask_var(&acpi_processor_perf->shared_cpu_map,
 323                                                                 GFP_KERNEL)) {
 324                 retval = -ENOMEM;
 325                 goto err05;
 326         }
 327
 328         if (acpi_processor_register_performance(acpi_processor_perf, 0)) {
 329                 retval = -EIO;
 330                 goto err1;
 331         }
 332
 333         if (acpi_processor_perf->control_register.space_id !=
 334                         ACPI_ADR_SPACE_FIXED_HARDWARE) {
 335                 retval = -ENODEV;
 336                 goto err2;
 337         }
 338
 339         if (acpi_processor_perf->status_register.space_id !=
 340                         ACPI_ADR_SPACE_FIXED_HARDWARE) {
 341                 retval = -ENODEV;
 342                 goto err2;
 343         }
 344
 345         number_scales = acpi_processor_perf->state_count;
 346
 347         if (number_scales < 2) {
 348                 retval = -ENODEV;
 349                 goto err2;
 350         }
 351
 352         powernow_table = kzalloc((sizeof(struct cpufreq_frequency_table) *
 353                                 (number_scales + 1)), GFP_KERNEL);
 354         if (!powernow_table) {
 355                 retval = -ENOMEM;
 356                 goto err2;
 357         }
 358
 359         pc.val = (unsigned long) acpi_processor_perf->states[0].control;
 360         for (i = 0; i < number_scales; i++) {
 361                 u8 fid, vid;
 362                 struct acpi_processor_px *state =
 363                         &acpi_processor_perf->states[i];
 364                 unsigned int speed, speed_mhz;
 365
 366                 pc.val = (unsigned long) state->control;
 367                 pr_debug("acpi:  P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
 368                          i,
 369                          (u32) state->core_frequency,
 370                          (u32) state->power,
 371                          (u32) state->transition_latency,
 372                          (u32) state->control,
 373                          pc.bits.sgtc);
 374
 375                 vid = pc.bits.vid;
 376                 fid = pc.bits.fid;
 377
 378                 powernow_table[i].frequency = fsb * fid_codes[fid] / 10;
 379                 powernow_table[i].index = fid; /* lower 8 bits */
 380                 powernow_table[i].index |= (vid << 8); /* upper 8 bits */
 381
 382                 speed = powernow_table[i].frequency;
 383                 speed_mhz = speed / 1000;
 384
 385                 /* processor_perflib will multiply the MHz value by 1000 to
 386                  * get a KHz value (e.g. 1266000). However, powernow-k7 works
 387                  * with true KHz values (e.g. 1266768). To ensure that all
 388                  * powernow frequencies are available, we must ensure that
 389                  * ACPI doesn't restrict them, so we round up the MHz value
 390                  * to ensure that perflib's computed KHz value is greater than
 391                  * or equal to powernow's KHz value.
 392                  */
 393                 if (speed % 1000 > 0)
 394                         speed_mhz++;
 395
 396                 if ((fid_codes[fid] % 10) == 5) {
 397                         if (have_a0 == 1)
 398                                 invalidate_entry(i);
 399                 }
 400
 401                 pr_debug("   FID: 0x%x (%d.%dx [%dMHz])  "
 402                          "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
 403                          fid_codes[fid] % 10, speed_mhz, vid,
 404                          mobile_vid_table[vid]/1000,
 405                          mobile_vid_table[vid]%1000);
 406
 407                 if (state->core_frequency != speed_mhz) {
 408                         state->core_frequency = speed_mhz;
 409                         pr_debug("   Corrected ACPI frequency to %d\n",
 410                                 speed_mhz);
 411                 }
 412
 413                 if (latency < pc.bits.sgtc)
 414                         latency = pc.bits.sgtc;
 415
 416                 if (speed < minimum_speed)
 417                         minimum_speed = speed;
 418                 if (speed > maximum_speed)
 419                         maximum_speed = speed;
 420         }
 421
 422         powernow_table[i].frequency = CPUFREQ_TABLE_END;
 423         powernow_table[i].index = 0;
 424
 425         /* notify BIOS that we exist */
 426         acpi_processor_notify_smm(THIS_MODULE);
 427
 428         return 0;
 429
 430 err2:
 431         acpi_processor_unregister_performance(acpi_processor_perf, 0);
 432 err1:
 433         free_cpumask_var(acpi_processor_perf->shared_cpu_map);
 434 err05:
 435         kfree(acpi_processor_perf);
 436 err0:
 437         printk(KERN_WARNING PFX "ACPI perflib can not be used on "
 438                         "this platform\n");
 439         acpi_processor_perf = NULL;
 440         return retval;
 441 }
 442 #else
 443 static int powernow_acpi_init(void)
 444 {
 445         printk(KERN_INFO PFX "no support for ACPI processor found."
 446                "  Please recompile your kernel with ACPI processor\n");
 447         return -EINVAL;
 448 }
 449 #endif
 450
 451 static void print_pst_entry(struct pst_s *pst, unsigned int j)
 452 {
 453         pr_debug("PST:%d (@%p)\n", j, pst);
 454         pr_debug(" cpuid: 0x%x  fsb: %d  maxFID: 0x%x  startvid: 0x%x\n",
 455                 pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid);
 456 }
 457
 458 static int powernow_decode_bios(int maxfid, int startvid)
 459 {
 460         struct psb_s *psb;
 461         struct pst_s *pst;
 462         unsigned int i, j;
 463         unsigned char *p;
 464         unsigned int etuple;
 465         unsigned int ret;
 466
 467         etuple = cpuid_eax(0x80000001);
 468
 469         for (i = 0xC0000; i < 0xffff0 ; i += 16) {
 470
 471                 p = phys_to_virt(i);
 472
 473                 if (memcmp(p, "AMDK7PNOW!",  10) == 0) {
 474                         pr_debug("Found PSB header at %p\n", p);
 475                         psb = (struct psb_s *) p;
 476                         pr_debug("Table version: 0x%x\n", psb->tableversion);
 477                         if (psb->tableversion != 0x12) {
 478                                 printk(KERN_INFO PFX "Sorry, only v1.2 tables"
 479                                                 " supported right now\n");
 480                                 return -ENODEV;
 481                         }
 482
 483                         pr_debug("Flags: 0x%x\n", psb->flags);
 484                         if ((psb->flags & 1) == 0)
 485                                 pr_debug("Mobile voltage regulator\n");
 486                         else
 487                                 pr_debug("Desktop voltage regulator\n");
 488
 489                         latency = psb->settlingtime;
 490                         if (latency < 100) {
 491                                 printk(KERN_INFO PFX "BIOS set settling time "
 492                                                 "to %d microseconds. "
 493                                                 "Should be at least 100. "
 494                                                 "Correcting.\n", latency);
 495                                 latency = 100;
 496                         }
 497                         pr_debug("Settling Time: %d microseconds.\n",
 498                                         psb->settlingtime);
 499                         pr_debug("Has %d PST tables. (Only dumping ones "
 500                                         "relevant to this CPU).\n",
 501                                         psb->numpst);
 502
 503                         p += sizeof(struct psb_s);
 504
 505                         pst = (struct pst_s *) p;
 506
 507                         for (j = 0; j < psb->numpst; j++) {
 508                                 pst = (struct pst_s *) p;
 509                                 number_scales = pst->numpstates;
 510
 511                                 if ((etuple == pst->cpuid) &&
 512                                     check_fsb(pst->fsbspeed) &&
 513                                     (maxfid == pst->maxfid) &&
 514                                     (startvid == pst->startvid)) {
 515                                         print_pst_entry(pst, j);
 516                                         p = (char *)pst + sizeof(struct pst_s);
 517                                         ret = get_ranges(p);
 518                                         return ret;
 519                                 } else {
 520                                         unsigned int k;
 521                                         p = (char *)pst + sizeof(struct pst_s);
 522                                         for (k = 0; k < number_scales; k++)
 523                                                 p += 2;
 524                                 }
 525                         }
 526                         printk(KERN_INFO PFX "No PST tables match this cpuid "
 527                                         "(0x%x)\n", etuple);
 528                         printk(KERN_INFO PFX "This is indicative of a broken "
 529                                         "BIOS.\n");
 530
 531                         return -EINVAL;
 532                 }
 533                 p++;
 534         }
 535
 536         return -ENODEV;
 537 }
 538
 539
 540 static int powernow_target(struct cpufreq_policy *policy,
 541                             unsigned int target_freq,
 542                             unsigned int relation)
 543 {
 544         unsigned int newstate;
 545
 546         if (cpufreq_frequency_table_target(policy, powernow_table, target_freq,
 547                                 relation, &newstate))
 548                 return -EINVAL;
 549
 550         change_speed(newstate);
 551
 552         return 0;
 553 }
 554
 555
 556 static int powernow_verify(struct cpufreq_policy *policy)
 557 {
 558         return cpufreq_frequency_table_verify(policy, powernow_table);
 559 }
 560
 561 /*
 562  * We use the fact that the bus frequency is somehow
 563  * a multiple of 100000/3 khz, then we compute sgtc according
 564  * to this multiple.
 565  * That way, we match more how AMD thinks all of that work.
 566  * We will then get the same kind of behaviour already tested under
 567  * the "well-known" other OS.
 568  */
 569 static int __cpuinit fixup_sgtc(void)
 570 {
 571         unsigned int sgtc;
 572         unsigned int m;
 573
 574         m = fsb / 3333;
 575         if ((m % 10) >= 5)
 576                 m += 5;
 577
 578         m /= 10;
 579
 580         sgtc = 100 * m * latency;
 581         sgtc = sgtc / 3;
 582         if (sgtc > 0xfffff) {
 583                 printk(KERN_WARNING PFX "SGTC too large %d\n", sgtc);
 584                 sgtc = 0xfffff;
 585         }
 586         return sgtc;
 587 }
 588
 589 static unsigned int powernow_get(unsigned int cpu)
 590 {
 591         union msr_fidvidstatus fidvidstatus;
 592         unsigned int cfid;
 593
 594         if (cpu)
 595                 return 0;
 596         rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
 597         cfid = fidvidstatus.bits.CFID;
 598
 599         return fsb * fid_codes[cfid] / 10;
 600 }
 601
 602
 603 static int __cpuinit acer_cpufreq_pst(const struct dmi_system_id *d)
 604 {
 605         printk(KERN_WARNING PFX
 606                 "%s laptop with broken PST tables in BIOS detected.\n",
 607                 d->ident);
 608         printk(KERN_WARNING PFX
 609                 "You need to downgrade to 3A21 (09/09/2002), or try a newer "
 610                 "BIOS than 3A71 (01/20/2003)\n");
 611         printk(KERN_WARNING PFX
 612                 "cpufreq scaling has been disabled as a result of this.\n");
 613         return 0;
 614 }
 615
 616 /*
 617  * Some Athlon laptops have really fucked PST tables.
 618  * A BIOS update is all that can save them.
 619  * Mention this, and disable cpufreq.
 620  */
 621 static struct dmi_system_id __cpuinitdata powernow_dmi_table[] = {
 622         {
 623                 .callback = acer_cpufreq_pst,
 624                 .ident = "Acer Aspire",
 625                 .matches = {
 626                         DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"),
 627                         DMI_MATCH(DMI_BIOS_VERSION, "3A71"),
 628                 },
 629         },
 630         { }
 631 };
 632
 633 static int __cpuinit powernow_cpu_init(struct cpufreq_policy *policy)
 634 {
 635         union msr_fidvidstatus fidvidstatus;
 636         int result;
 637
 638         if (policy->cpu != 0)
 639                 return -ENODEV;
 640
 641         rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
 642
 643         recalibrate_cpu_khz();
 644
 645         fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID];
 646         if (!fsb) {
 647                 printk(KERN_WARNING PFX "can not determine bus frequency\n");
 648                 return -EINVAL;
 649         }
 650         pr_debug("FSB: %3dMHz\n", fsb/1000);
 651
 652         if (dmi_check_system(powernow_dmi_table) || acpi_force) {
 653                 printk(KERN_INFO PFX "PSB/PST known to be broken.  "
 654                                 "Trying ACPI instead\n");
 655                 result = powernow_acpi_init();
 656         } else {
 657                 result = powernow_decode_bios(fidvidstatus.bits.MFID,
 658                                 fidvidstatus.bits.SVID);
 659                 if (result) {
 660                         printk(KERN_INFO PFX "Trying ACPI perflib\n");
 661                         maximum_speed = 0;
 662                         minimum_speed = -1;
 663                         latency = 0;
 664                         result = powernow_acpi_init();
 665                         if (result) {
 666                                 printk(KERN_INFO PFX
 667                                         "ACPI and legacy methods failed\n");
 668                         }
 669                 } else {
 670                         /* SGTC use the bus clock as timer */
 671                         latency = fixup_sgtc();
 672                         printk(KERN_INFO PFX "SGTC: %d\n", latency);
 673                 }
 674         }
 675
 676         if (result)
 677                 return result;
 678
 679         printk(KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n",
 680                                 minimum_speed/1000, maximum_speed/1000);
 681
 682         policy->cpuinfo.transition_latency =
 683                 cpufreq_scale(2000000UL, fsb, latency);
 684
 685         policy->cur = powernow_get(0);
 686
 687         cpufreq_frequency_table_get_attr(powernow_table, policy->cpu);
 688
 689         return cpufreq_frequency_table_cpuinfo(policy, powernow_table);
 690 }
 691
 692 static int powernow_cpu_exit(struct cpufreq_policy *policy)
 693 {
 694         cpufreq_frequency_table_put_attr(policy->cpu);
 695
 696 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
 697         if (acpi_processor_perf) {
 698                 acpi_processor_unregister_performance(acpi_processor_perf, 0);
 699                 free_cpumask_var(acpi_processor_perf->shared_cpu_map);
 700                 kfree(acpi_processor_perf);
 701         }
 702 #endif
 703
 704         kfree(powernow_table);
 705         return 0;
 706 }
 707
 708 static struct freq_attr *powernow_table_attr[] = {
 709         &cpufreq_freq_attr_scaling_available_freqs,
 710         NULL,
 711 };
 712
 713 static struct cpufreq_driver powernow_driver = {
 714         .verify         = powernow_verify,
 715         .target         = powernow_target,
 716         .get            = powernow_get,
 717 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
 718         .bios_limit     = acpi_processor_get_bios_limit,
 719 #endif
 720         .init           = powernow_cpu_init,
 721         .exit           = powernow_cpu_exit,
 722         .name           = "powernow-k7",
 723         .owner          = THIS_MODULE,
 724         .attr           = powernow_table_attr,
 725 };
 726
 727 static int __init powernow_init(void)
 728 {
 729         if (check_powernow() == 0)
 730                 return -ENODEV;
 731         return cpufreq_register_driver(&powernow_driver);
 732 }
 733
 734
 735 static void __exit powernow_exit(void)
 736 {
 737         cpufreq_unregister_driver(&powernow_driver);
 738 }
 739
 740 module_param(acpi_force,  int, 0444);
 741 MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");
 742
 743 MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
 744 MODULE_DESCRIPTION("Powernow driver for AMD K7 processors.");
 745 MODULE_LICENSE("GPL");
 746
 747 late_initcall(powernow_init);
 748 module_exit(powernow_exit);
 749