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(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].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(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].driver_data = fid; /* lower 8 bits */
 377                powernow_table[i].driver_data |= (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].driver_data = 0;
 421
 422        /* notify BIOS that we exist */
 423        acpi_processor_notify_smm(THIS_MODULE);
 424
 425        return 0;
 426
 427err2:
 428        acpi_processor_unregister_performance(acpi_processor_perf, 0);
 429err1:
 430        free_cpumask_var(acpi_processor_perf->shared_cpu_map);
 431err05:
 432        kfree(acpi_processor_perf);
 433err0:
 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
 440static 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
 448static 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
 455static 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
 537static 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
 553static 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 */
 566static int 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
 586static 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
 600static int 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 */
 618static struct dmi_system_id 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
 630static int 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
 689static 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
 705static struct freq_attr *powernow_table_attr[] = {
 706        &cpufreq_freq_attr_scaling_available_freqs,
 707        NULL,
 708};
 709
 710static 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
 724static int __init powernow_init(void)
 725{
 726        if (check_powernow() == 0)
 727                return -ENODEV;
 728        return cpufreq_register_driver(&powernow_driver);
 729}
 730
 731
 732static void __exit powernow_exit(void)
 733{
 734        cpufreq_unregister_driver(&powernow_driver);
 735}
 736
 737module_param(acpi_force,  int, 0444);
 738MODULE_PARM_DESC(acpi_force, "Force ACPI to be used.");
 739
 740MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
 741MODULE_DESCRIPTION("Powernow driver for AMD K7 processors.");
 742MODULE_LICENSE("GPL");
 743
 744late_initcall(powernow_init);
 745module_exit(powernow_exit);
 746
 747
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