linux/drivers/cpufreq/powernow-k7.c
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   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
  42struct psb_s {
  43        u8 signature[10];
  44        u8 tableversion;
  45        u8 flags;
  46        u16 settlingtime;
  47        u8 reserved1;
  48        u8 numpst;
  49};
  50
  51struct 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
  60union 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. */
  72static 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. */
  80static 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
  91static int acpi_force;
  92
  93static struct cpufreq_frequency_table *powernow_table;
  94
  95static unsigned int can_scale_bus;
  96static unsigned int can_scale_vid;
  97static unsigned int minimum_speed = -1;
  98static unsigned int maximum_speed;
  99static unsigned int number_scales;
 100static unsigned int fsb;
 101static unsigned int latency;
 102static char have_a0;
 103
 104static 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
 113static const struct x86_cpu_id powernow_k7_cpuids[] = {
 114        { X86_VENDOR_AMD, 6, },
 115        {}
 116};
 117MODULE_DEVICE_TABLE(x86cpu, powernow_k7_cpuids);
 118
 119static 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
 168static void invalidate_entry(unsigned int entry)
 169{
 170        powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
 171}
 172#endif
 173
 174static 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(*powernow_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].driver_data = 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].driver_data |= (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].driver_data = 0;
 216
 217        return 0;
 218}
 219
 220
 221static 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
 236static 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
 251static 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].driver_data & 0xFF;
 264        vid = (powernow_table[index].driver_data & 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
 299static struct acpi_processor_performance *acpi_processor_perf;
 300
 301static 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(*acpi_processor_perf), GFP_KERNEL);
 313        if (!acpi_processor_perf) {
 314                retval = -ENOMEM;
 315                goto err0;
 316        }
 317
 318        if (!zalloc_cpumask_var(&acpi_processor_perf->shared_cpu_map,
 319                                                                GFP_KERNEL)) {
 320                retval = -ENOMEM;
 321                goto err05;
 322        }
 323
 324        if (acpi_processor_register_performance(acpi_processor_perf, 0)) {
 325                retval = -EIO;
 326                goto err1;
 327        }
 328
 329        if (acpi_processor_perf->control_register.space_id !=
 330                        ACPI_ADR_SPACE_FIXED_HARDWARE) {
 331                retval = -ENODEV;
 332                goto err2;
 333        }
 334
 335        if (acpi_processor_perf->status_register.space_id !=
 336                        ACPI_ADR_SPACE_FIXED_HARDWARE) {
 337                retval = -ENODEV;
 338                goto err2;
 339        }
 340
 341        number_scales = acpi_processor_perf->state_count;
 342
 343        if (number_scales < 2) {
 344                retval = -ENODEV;
 345                goto err2;
 346        }
 347
 348        powernow_table = kzalloc((sizeof(*powernow_table) *
 349                                (number_scales + 1)), GFP_KERNEL);
 350        if (!powernow_table) {
 351                retval = -ENOMEM;
 352                goto err2;
 353        }
 354
 355        pc.val = (unsigned long) acpi_processor_perf->states[0].control;
 356        for (i = 0; i < number_scales; i++) {
 357                u8 fid, vid;
 358                struct acpi_processor_px *state =
 359                        &acpi_processor_perf->states[i];
 360                unsigned int speed, speed_mhz;
 361
 362                pc.val = (unsigned long) state->control;
 363                pr_debug("acpi:  P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
 364                         i,
 365                         (u32) state->core_frequency,
 366                         (u32) state->power,
 367                         (u32) state->transition_latency,
 368                         (u32) state->control,
 369                         pc.bits.sgtc);
 370
 371                vid = pc.bits.vid;
 372                fid = pc.bits.fid;
 373
 374                powernow_table[i].frequency = fsb * fid_codes[fid] / 10;
 375                powernow_table[i].driver_data = fid; /* lower 8 bits */
 376                powernow_table[i].driver_data |= (vid << 8); /* upper 8 bits */
 377
 378                speed = powernow_table[i].frequency;
 379                speed_mhz = speed / 1000;
 380
 381                /* processor_perflib will multiply the MHz value by 1000 to
 382                 * get a KHz value (e.g. 1266000). However, powernow-k7 works
 383                 * with true KHz values (e.g. 1266768). To ensure that all
 384                 * powernow frequencies are available, we must ensure that
 385                 * ACPI doesn't restrict them, so we round up the MHz value
 386                 * to ensure that perflib's computed KHz value is greater than
 387                 * or equal to powernow's KHz value.
 388                 */
 389                if (speed % 1000 > 0)
 390                        speed_mhz++;
 391
 392                if ((fid_codes[fid] % 10) == 5) {
 393                        if (have_a0 == 1)
 394                                invalidate_entry(i);
 395                }
 396
 397                pr_debug("   FID: 0x%x (%d.%dx [%dMHz])  "
 398                         "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10,
 399                         fid_codes[fid] % 10, speed_mhz, vid,
 400                         mobile_vid_table[vid]/1000,
 401                         mobile_vid_table[vid]%1000);
 402
 403                if (state->core_frequency != speed_mhz) {
 404                        state->core_frequency = speed_mhz;
 405                        pr_debug("   Corrected ACPI frequency to %d\n",
 406                                speed_mhz);
 407                }
 408
 409                if (latency < pc.bits.sgtc)
 410                        latency = pc.bits.sgtc;
 411
 412                if (speed < minimum_speed)
 413                        minimum_speed = speed;
 414                if (speed > maximum_speed)
 415                        maximum_speed = speed;
 416        }
 417
 418        powernow_table[i].frequency = CPUFREQ_TABLE_END;
 419        powernow_table[i].driver_data = 0;
 420
 421        /* notify BIOS that we exist */
 422        acpi_processor_notify_smm(THIS_MODULE);
 423
 424        return 0;
 425
 426err2:
 427        acpi_processor_unregister_performance(acpi_processor_perf, 0);
 428err1:
 429        free_cpumask_var(acpi_processor_perf->shared_cpu_map);
 430err05:
 431        kfree(acpi_processor_perf);
 432err0:
 433        printk(KERN_WARNING PFX "ACPI perflib can not be used on "
 434                        "this platform\n");
 435        acpi_processor_perf = NULL;
 436        return retval;
 437}
 438#else
 439static int powernow_acpi_init(void)
 440{
 441        printk(KERN_INFO PFX "no support for ACPI processor found."
 442               "  Please recompile your kernel with ACPI processor\n");
 443        return -EINVAL;
 444}
 445#endif
 446
 447static void print_pst_entry(struct pst_s *pst, unsigned int j)
 448{
 449        pr_debug("PST:%d (@%p)\n", j, pst);
 450        pr_debug(" cpuid: 0x%x  fsb: %d  maxFID: 0x%x  startvid: 0x%x\n",
 451                pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid);
 452}
 453
 454static int powernow_decode_bios(int maxfid, int startvid)
 455{
 456        struct psb_s *psb;
 457        struct pst_s *pst;
 458        unsigned int i, j;
 459        unsigned char *p;
 460        unsigned int etuple;
 461        unsigned int ret;
 462
 463        etuple = cpuid_eax(0x80000001);
 464
 465        for (i = 0xC0000; i < 0xffff0 ; i += 16) {
 466
 467                p = phys_to_virt(i);
 468
 469                if (memcmp(p, "AMDK7PNOW!",  10) == 0) {
 470                        pr_debug("Found PSB header at %p\n", p);
 471                        psb = (struct psb_s *) p;
 472                        pr_debug("Table version: 0x%x\n", psb->tableversion);
 473                        if (psb->tableversion != 0x12) {
 474                                printk(KERN_INFO PFX "Sorry, only v1.2 tables"
 475                                                " supported right now\n");
 476                                return -ENODEV;
 477                        }
 478
 479                        pr_debug("Flags: 0x%x\n", psb->flags);
 480                        if ((psb->flags & 1) == 0)
 481                                pr_debug("Mobile voltage regulator\n");
 482                        else
 483                                pr_debug("Desktop voltage regulator\n");
 484
 485                        latency = psb->settlingtime;
 486                        if (latency < 100) {
 487                                printk(KERN_INFO PFX "BIOS set settling time "
 488                                                "to %d microseconds. "
 489                                                "Should be at least 100. "
 490                                                "Correcting.\n", latency);
 491                                latency = 100;
 492                        }
 493                        pr_debug("Settling Time: %d microseconds.\n",
 494                                        psb->settlingtime);
 495                        pr_debug("Has %d PST tables. (Only dumping ones "
 496                                        "relevant to this CPU).\n",
 497                                        psb->numpst);
 498
 499                        p += sizeof(*psb);
 500
 501                        pst = (struct pst_s *) p;
 502
 503                        for (j = 0; j < psb->numpst; j++) {
 504                                pst = (struct pst_s *) p;
 505                                number_scales = pst->numpstates;
 506
 507                                if ((etuple == pst->cpuid) &&
 508                                    check_fsb(pst->fsbspeed) &&
 509                                    (maxfid == pst->maxfid) &&
 510                                    (startvid == pst->startvid)) {
 511                                        print_pst_entry(pst, j);
 512                                        p = (char *)pst + sizeof(*pst);
 513                                        ret = get_ranges(p);
 514                                        return ret;
 515                                } else {
 516                                        unsigned int k;
 517                                        p = (char *)pst + sizeof(*pst);
 518                                        for (k = 0; k < number_scales; k++)
 519                                                p += 2;
 520                                }
 521                        }
 522                        printk(KERN_INFO PFX "No PST tables match this cpuid "
 523                                        "(0x%x)\n", etuple);
 524                        printk(KERN_INFO PFX "This is indicative of a broken "
 525                                        "BIOS.\n");
 526
 527                        return -EINVAL;
 528                }
 529                p++;
 530        }
 531
 532        return -ENODEV;
 533}
 534
 535
 536static int powernow_target(struct cpufreq_policy *policy,
 537                            unsigned int target_freq,
 538                            unsigned int relation)
 539{
 540        unsigned int newstate;
 541
 542        if (cpufreq_frequency_table_target(policy, powernow_table, target_freq,
 543                                relation, &newstate))
 544                return -EINVAL;
 545
 546        change_speed(policy, newstate);
 547
 548        return 0;
 549}
 550
 551
 552static int powernow_verify(struct cpufreq_policy *policy)
 553{
 554        return cpufreq_frequency_table_verify(policy, powernow_table);
 555}
 556
 557/*
 558 * We use the fact that the bus frequency is somehow
 559 * a multiple of 100000/3 khz, then we compute sgtc according
 560 * to this multiple.
 561 * That way, we match more how AMD thinks all of that work.
 562 * We will then get the same kind of behaviour already tested under
 563 * the "well-known" other OS.
 564 */
 565static int fixup_sgtc(void)
 566{
 567        unsigned int sgtc;
 568        unsigned int m;
 569
 570        m = fsb / 3333;
 571        if ((m % 10) >= 5)
 572                m += 5;
 573
 574        m /= 10;
 575
 576        sgtc = 100 * m * latency;
 577        sgtc = sgtc / 3;
 578        if (sgtc > 0xfffff) {
 579                printk(KERN_WARNING PFX "SGTC too large %d\n", sgtc);
 580                sgtc = 0xfffff;
 581        }
 582        return sgtc;
 583}
 584
 585static unsigned int powernow_get(unsigned int cpu)
 586{
 587        union msr_fidvidstatus fidvidstatus;
 588        unsigned int cfid;
 589
 590        if (cpu)
 591                return 0;
 592        rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
 593        cfid = fidvidstatus.bits.CFID;
 594
 595        return fsb * fid_codes[cfid] / 10;
 596}
 597
 598
 599static int acer_cpufreq_pst(const struct dmi_system_id *d)
 600{
 601        printk(KERN_WARNING PFX
 602                "%s laptop with broken PST tables in BIOS detected.\n",
 603                d->ident);
 604        printk(KERN_WARNING PFX
 605                "You need to downgrade to 3A21 (09/09/2002), or try a newer "
 606                "BIOS than 3A71 (01/20/2003)\n");
 607        printk(KERN_WARNING PFX
 608                "cpufreq scaling has been disabled as a result of this.\n");
 609        return 0;
 610}
 611
 612/*
 613 * Some Athlon laptops have really fucked PST tables.
 614 * A BIOS update is all that can save them.
 615 * Mention this, and disable cpufreq.
 616 */
 617static struct dmi_system_id powernow_dmi_table[] = {
 618        {
 619                .callback = acer_cpufreq_pst,
 620                .ident = "Acer Aspire",
 621                .matches = {
 622                        DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"),
 623                        DMI_MATCH(DMI_BIOS_VERSION, "3A71"),
 624                },
 625        },
 626        { }
 627};
 628
 629static int powernow_cpu_init(struct cpufreq_policy *policy)
 630{
 631        union msr_fidvidstatus fidvidstatus;
 632        int result;
 633
 634        if (policy->cpu != 0)
 635                return -ENODEV;
 636
 637        rdmsrl(MSR_K7_FID_VID_STATUS, fidvidstatus.val);
 638
 639        recalibrate_cpu_khz();
 640
 641        fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID];
 642        if (!fsb) {
 643                printk(KERN_WARNING PFX "can not determine bus frequency\n");
 644                return -EINVAL;
 645        }
 646        pr_debug("FSB: %3dMHz\n", fsb/1000);
 647
 648        if (dmi_check_system(powernow_dmi_table) || acpi_force) {
 649                printk(KERN_INFO PFX "PSB/PST known to be broken.  "
 650                                "Trying ACPI instead\n");
 651                result = powernow_acpi_init();
 652        } else {
 653                result = powernow_decode_bios(fidvidstatus.bits.MFID,
 654                                fidvidstatus.bits.SVID);
 655                if (result) {
 656                        printk(KERN_INFO PFX "Trying ACPI perflib\n");
 657                        maximum_speed = 0;
 658                        minimum_speed = -1;
 659                        latency = 0;
 660                        result = powernow_acpi_init();
 661                        if (result) {
 662                                printk(KERN_INFO PFX
 663                                        "ACPI and legacy methods failed\n");
 664                        }
 665                } else {
 666                        /* SGTC use the bus clock as timer */
 667                        latency = fixup_sgtc();
 668                        printk(KERN_INFO PFX "SGTC: %d\n", latency);
 669                }
 670        }
 671
 672        if (result)
 673                return result;
 674
 675        printk(KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n",
 676                                minimum_speed/1000, maximum_speed/1000);
 677
 678        policy->cpuinfo.transition_latency =
 679                cpufreq_scale(2000000UL, fsb, latency);
 680
 681        policy->cur = powernow_get(0);
 682
 683        cpufreq_frequency_table_get_attr(powernow_table, policy->cpu);
 684
 685        return cpufreq_frequency_table_cpuinfo(policy, powernow_table);
 686}
 687
 688static int powernow_cpu_exit(struct cpufreq_policy *policy)
 689{
 690        cpufreq_frequency_table_put_attr(policy->cpu);
 691
 692#ifdef CONFIG_X86_POWERNOW_K7_ACPI
 693        if (acpi_processor_perf) {
 694                acpi_processor_unregister_performance(acpi_processor_perf, 0);
 695                free_cpumask_var(acpi_processor_perf->shared_cpu_map);
 696                kfree(acpi_processor_perf);
 697        }
 698#endif
 699
 700        kfree(powernow_table);
 701        return 0;
 702}
 703
 704static struct freq_attr *powernow_table_attr[] = {
 705        &cpufreq_freq_attr_scaling_available_freqs,
 706        NULL,
 707};
 708
 709static struct cpufreq_driver powernow_driver = {
 710        .verify         = powernow_verify,
 711        .target         = powernow_target,
 712        .get            = powernow_get,
 713#ifdef CONFIG_X86_POWERNOW_K7_ACPI
 714        .bios_limit     = acpi_processor_get_bios_limit,
 715#endif
 716        .init           = powernow_cpu_init,
 717        .exit           = powernow_cpu_exit,
 718        .name           = "powernow-k7",
 719        .attr           = powernow_table_attr,
 720};
 721
 722static int __init powernow_init(void)
 723{
 724        if (check_powernow() == 0)
 725                return -ENODEV;
 726        return cpufreq_register_driver(&powernow_driver);
 727}
 728
 729
 730static void __exit powernow_exit(void)
 731{
 732        cpufreq_unregister_driver(&powernow_driver);
 733}
 734
 735module_param(acpi_force,  int, 0444);
 736MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");
 737
 738MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
 739MODULE_DESCRIPTION("Powernow driver for AMD K7 processors.");
 740MODULE_LICENSE("GPL");
 741
 742late_initcall(powernow_init);
 743module_exit(powernow_exit);
 744
 745
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