drivers/cpufreq/powernow-k8.c

   1 /*
   2  *   (c) 2003-2012 Advanced Micro Devices, Inc.
   3  *  Your use of this code is subject to the terms and conditions of the
   4  *  GNU general public license version 2. See "COPYING" or
   5  *  http://www.gnu.org/licenses/gpl.html
   6  *
   7  *  Maintainer:
   8  *  Andreas Herrmann <andreas.herrmann3@amd.com>
   9  *
  10  *  Based on the powernow-k7.c module written by Dave Jones.
  11  *  (C) 2003 Dave Jones on behalf of SuSE Labs
  12  *  (C) 2004 Dominik Brodowski <linux@brodo.de>
  13  *  (C) 2004 Pavel Machek <pavel@ucw.cz>
  14  *  Licensed under the terms of the GNU GPL License version 2.
  15  *  Based upon datasheets & sample CPUs kindly provided by AMD.
  16  *
  17  *  Valuable input gratefully received from Dave Jones, Pavel Machek,
  18  *  Dominik Brodowski, Jacob Shin, and others.
  19  *  Originally developed by Paul Devriendt.
  20  *
  21  *  Processor information obtained from Chapter 9 (Power and Thermal
  22  *  Management) of the "BIOS and Kernel Developer's Guide (BKDG) for
  23  *  the AMD Athlon 64 and AMD Opteron Processors" and section "2.x
  24  *  Power Management" in BKDGs for newer AMD CPU families.
  25  *
  26  *  Tables for specific CPUs can be inferred from AMD's processor
  27  *  power and thermal data sheets, (e.g. 30417.pdf, 30430.pdf, 43375.pdf)
  28  */
  29
  30 #include <linux/kernel.h>
  31 #include <linux/smp.h>
  32 #include <linux/module.h>
  33 #include <linux/init.h>
  34 #include <linux/cpufreq.h>
  35 #include <linux/slab.h>
  36 #include <linux/string.h>
  37 #include <linux/cpumask.h>
  38 #include <linux/sched.h>        /* for current / set_cpus_allowed() */
  39 #include <linux/io.h>
  40 #include <linux/delay.h>
  41
  42 #include <asm/msr.h>
  43 #include <asm/cpu_device_id.h>
  44
  45 #include <linux/acpi.h>
  46 #include <linux/mutex.h>
  47 #include <acpi/processor.h>
  48
  49 #define PFX "powernow-k8: "
  50 #define VERSION "version 2.20.00"
  51 #include "powernow-k8.h"
  52
  53 /* serialize freq changes  */
  54 static DEFINE_MUTEX(fidvid_mutex);
  55
  56 static DEFINE_PER_CPU(struct powernow_k8_data *, powernow_data);
  57
  58 static struct cpufreq_driver cpufreq_amd64_driver;
  59
  60 #ifndef CONFIG_SMP
  61 static inline const struct cpumask *cpu_core_mask(int cpu)
  62 {
  63         return cpumask_of(0);
  64 }
  65 #endif
  66
  67 /* Return a frequency in MHz, given an input fid */
  68 static u32 find_freq_from_fid(u32 fid)
  69 {
  70         return 800 + (fid * 100);
  71 }
  72
  73 /* Return a frequency in KHz, given an input fid */
  74 static u32 find_khz_freq_from_fid(u32 fid)
  75 {
  76         return 1000 * find_freq_from_fid(fid);
  77 }
  78
  79 /* Return the vco fid for an input fid
  80  *
  81  * Each "low" fid has corresponding "high" fid, and you can get to "low" fids
  82  * only from corresponding high fids. This returns "high" fid corresponding to
  83  * "low" one.
  84  */
  85 static u32 convert_fid_to_vco_fid(u32 fid)
  86 {
  87         if (fid < HI_FID_TABLE_BOTTOM)
  88                 return 8 + (2 * fid);
  89         else
  90                 return fid;
  91 }
  92
  93 /*
  94  * Return 1 if the pending bit is set. Unless we just instructed the processor
  95  * to transition to a new state, seeing this bit set is really bad news.
  96  */
  97 static int pending_bit_stuck(void)
  98 {
  99         u32 lo, hi;
 100
 101         rdmsr(MSR_FIDVID_STATUS, lo, hi);
 102         return lo & MSR_S_LO_CHANGE_PENDING ? 1 : 0;
 103 }
 104
 105 /*
 106  * Update the global current fid / vid values from the status msr.
 107  * Returns 1 on error.
 108  */
 109 static int query_current_values_with_pending_wait(struct powernow_k8_data *data)
 110 {
 111         u32 lo, hi;
 112         u32 i = 0;
 113
 114         do {
 115                 if (i++ > 10000) {
 116                         pr_debug("detected change pending stuck\n");
 117                         return 1;
 118                 }
 119                 rdmsr(MSR_FIDVID_STATUS, lo, hi);
 120         } while (lo & MSR_S_LO_CHANGE_PENDING);
 121
 122         data->currvid = hi & MSR_S_HI_CURRENT_VID;
 123         data->currfid = lo & MSR_S_LO_CURRENT_FID;
 124
 125         return 0;
 126 }
 127
 128 /* the isochronous relief time */
 129 static void count_off_irt(struct powernow_k8_data *data)
 130 {
 131         udelay((1 << data->irt) * 10);
 132         return;
 133 }
 134
 135 /* the voltage stabilization time */
 136 static void count_off_vst(struct powernow_k8_data *data)
 137 {
 138         udelay(data->vstable * VST_UNITS_20US);
 139         return;
 140 }
 141
 142 /* need to init the control msr to a safe value (for each cpu) */
 143 static void fidvid_msr_init(void)
 144 {
 145         u32 lo, hi;
 146         u8 fid, vid;
 147
 148         rdmsr(MSR_FIDVID_STATUS, lo, hi);
 149         vid = hi & MSR_S_HI_CURRENT_VID;
 150         fid = lo & MSR_S_LO_CURRENT_FID;
 151         lo = fid | (vid << MSR_C_LO_VID_SHIFT);
 152         hi = MSR_C_HI_STP_GNT_BENIGN;
 153         pr_debug("cpu%d, init lo 0x%x, hi 0x%x\n", smp_processor_id(), lo, hi);
 154         wrmsr(MSR_FIDVID_CTL, lo, hi);
 155 }
 156
 157 /* write the new fid value along with the other control fields to the msr */
 158 static int write_new_fid(struct powernow_k8_data *data, u32 fid)
 159 {
 160         u32 lo;
 161         u32 savevid = data->currvid;
 162         u32 i = 0;
 163
 164         if ((fid & INVALID_FID_MASK) || (data->currvid & INVALID_VID_MASK)) {
 165                 printk(KERN_ERR PFX "internal error - overflow on fid write\n");
 166                 return 1;
 167         }
 168
 169         lo = fid;
 170         lo |= (data->currvid << MSR_C_LO_VID_SHIFT);
 171         lo |= MSR_C_LO_INIT_FID_VID;
 172
 173         pr_debug("writing fid 0x%x, lo 0x%x, hi 0x%x\n",
 174                 fid, lo, data->plllock * PLL_LOCK_CONVERSION);
 175
 176         do {
 177                 wrmsr(MSR_FIDVID_CTL, lo, data->plllock * PLL_LOCK_CONVERSION);
 178                 if (i++ > 100) {
 179                         printk(KERN_ERR PFX
 180                                 "Hardware error - pending bit very stuck - "
 181                                 "no further pstate changes possible\n");
 182                         return 1;
 183                 }
 184         } while (query_current_values_with_pending_wait(data));
 185
 186         count_off_irt(data);
 187
 188         if (savevid != data->currvid) {
 189                 printk(KERN_ERR PFX
 190                         "vid change on fid trans, old 0x%x, new 0x%x\n",
 191                         savevid, data->currvid);
 192                 return 1;
 193         }
 194
 195         if (fid != data->currfid) {
 196                 printk(KERN_ERR PFX
 197                         "fid trans failed, fid 0x%x, curr 0x%x\n", fid,
 198                         data->currfid);
 199                 return 1;
 200         }
 201
 202         return 0;
 203 }
 204
 205 /* Write a new vid to the hardware */
 206 static int write_new_vid(struct powernow_k8_data *data, u32 vid)
 207 {
 208         u32 lo;
 209         u32 savefid = data->currfid;
 210         int i = 0;
 211
 212         if ((data->currfid & INVALID_FID_MASK) || (vid & INVALID_VID_MASK)) {
 213                 printk(KERN_ERR PFX "internal error - overflow on vid write\n");
 214                 return 1;
 215         }
 216
 217         lo = data->currfid;
 218         lo |= (vid << MSR_C_LO_VID_SHIFT);
 219         lo |= MSR_C_LO_INIT_FID_VID;
 220
 221         pr_debug("writing vid 0x%x, lo 0x%x, hi 0x%x\n",
 222                 vid, lo, STOP_GRANT_5NS);
 223
 224         do {
 225                 wrmsr(MSR_FIDVID_CTL, lo, STOP_GRANT_5NS);
 226                 if (i++ > 100) {
 227                         printk(KERN_ERR PFX "internal error - pending bit "
 228                                         "very stuck - no further pstate "
 229                                         "changes possible\n");
 230                         return 1;
 231                 }
 232         } while (query_current_values_with_pending_wait(data));
 233
 234         if (savefid != data->currfid) {
 235                 printk(KERN_ERR PFX "fid changed on vid trans, old "
 236                         "0x%x new 0x%x\n",
 237                        savefid, data->currfid);
 238                 return 1;
 239         }
 240
 241         if (vid != data->currvid) {
 242                 printk(KERN_ERR PFX "vid trans failed, vid 0x%x, "
 243                                 "curr 0x%x\n",
 244                                 vid, data->currvid);
 245                 return 1;
 246         }
 247
 248         return 0;
 249 }
 250
 251 /*
 252  * Reduce the vid by the max of step or reqvid.
 253  * Decreasing vid codes represent increasing voltages:
 254  * vid of 0 is 1.550V, vid of 0x1e is 0.800V, vid of VID_OFF is off.
 255  */
 256 static int decrease_vid_code_by_step(struct powernow_k8_data *data,
 257                 u32 reqvid, u32 step)
 258 {
 259         if ((data->currvid - reqvid) > step)
 260                 reqvid = data->currvid - step;
 261
 262         if (write_new_vid(data, reqvid))
 263                 return 1;
 264
 265         count_off_vst(data);
 266
 267         return 0;
 268 }
 269
 270 /* Change Opteron/Athlon64 fid and vid, by the 3 phases. */
 271 static int transition_fid_vid(struct powernow_k8_data *data,
 272                 u32 reqfid, u32 reqvid)
 273 {
 274         if (core_voltage_pre_transition(data, reqvid, reqfid))
 275                 return 1;
 276
 277         if (core_frequency_transition(data, reqfid))
 278                 return 1;
 279
 280         if (core_voltage_post_transition(data, reqvid))
 281                 return 1;
 282
 283         if (query_current_values_with_pending_wait(data))
 284                 return 1;
 285
 286         if ((reqfid != data->currfid) || (reqvid != data->currvid)) {
 287                 printk(KERN_ERR PFX "failed (cpu%d): req 0x%x 0x%x, "
 288                                 "curr 0x%x 0x%x\n",
 289                                 smp_processor_id(),
 290                                 reqfid, reqvid, data->currfid, data->currvid);
 291                 return 1;
 292         }
 293
 294         pr_debug("transitioned (cpu%d): new fid 0x%x, vid 0x%x\n",
 295                 smp_processor_id(), data->currfid, data->currvid);
 296
 297         return 0;
 298 }
 299
 300 /* Phase 1 - core voltage transition ... setup voltage */
 301 static int core_voltage_pre_transition(struct powernow_k8_data *data,
 302                 u32 reqvid, u32 reqfid)
 303 {
 304         u32 rvosteps = data->rvo;
 305         u32 savefid = data->currfid;
 306         u32 maxvid, lo, rvomult = 1;
 307
 308         pr_debug("ph1 (cpu%d): start, currfid 0x%x, currvid 0x%x, "
 309                 "reqvid 0x%x, rvo 0x%x\n",
 310                 smp_processor_id(),
 311                 data->currfid, data->currvid, reqvid, data->rvo);
 312
 313         if ((savefid < LO_FID_TABLE_TOP) && (reqfid < LO_FID_TABLE_TOP))
 314                 rvomult = 2;
 315         rvosteps *= rvomult;
 316         rdmsr(MSR_FIDVID_STATUS, lo, maxvid);
 317         maxvid = 0x1f & (maxvid >> 16);
 318         pr_debug("ph1 maxvid=0x%x\n", maxvid);
 319         if (reqvid < maxvid) /* lower numbers are higher voltages */
 320                 reqvid = maxvid;
 321
 322         while (data->currvid > reqvid) {
 323                 pr_debug("ph1: curr 0x%x, req vid 0x%x\n",
 324                         data->currvid, reqvid);
 325                 if (decrease_vid_code_by_step(data, reqvid, data->vidmvs))
 326                         return 1;
 327         }
 328
 329         while ((rvosteps > 0) &&
 330                         ((rvomult * data->rvo + data->currvid) > reqvid)) {
 331                 if (data->currvid == maxvid) {
 332                         rvosteps = 0;
 333                 } else {
 334                         pr_debug("ph1: changing vid for rvo, req 0x%x\n",
 335                                 data->currvid - 1);
 336                         if (decrease_vid_code_by_step(data, data->currvid-1, 1))
 337                                 return 1;
 338                         rvosteps--;
 339                 }
 340         }
 341
 342         if (query_current_values_with_pending_wait(data))
 343                 return 1;
 344
 345         if (savefid != data->currfid) {
 346                 printk(KERN_ERR PFX "ph1 err, currfid changed 0x%x\n",
 347                                 data->currfid);
 348                 return 1;
 349         }
 350
 351         pr_debug("ph1 complete, currfid 0x%x, currvid 0x%x\n",
 352                 data->currfid, data->currvid);
 353
 354         return 0;
 355 }
 356
 357 /* Phase 2 - core frequency transition */
 358 static int core_frequency_transition(struct powernow_k8_data *data, u32 reqfid)
 359 {
 360         u32 vcoreqfid, vcocurrfid, vcofiddiff;
 361         u32 fid_interval, savevid = data->currvid;
 362
 363         if (data->currfid == reqfid) {
 364                 printk(KERN_ERR PFX "ph2 null fid transition 0x%x\n",
 365                                 data->currfid);
 366                 return 0;
 367         }
 368
 369         pr_debug("ph2 (cpu%d): starting, currfid 0x%x, currvid 0x%x, "
 370                 "reqfid 0x%x\n",
 371                 smp_processor_id(),
 372                 data->currfid, data->currvid, reqfid);
 373
 374         vcoreqfid = convert_fid_to_vco_fid(reqfid);
 375         vcocurrfid = convert_fid_to_vco_fid(data->currfid);
 376         vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
 377             : vcoreqfid - vcocurrfid;
 378
 379         if ((reqfid <= LO_FID_TABLE_TOP) && (data->currfid <= LO_FID_TABLE_TOP))
 380                 vcofiddiff = 0;
 381
 382         while (vcofiddiff > 2) {
 383                 (data->currfid & 1) ? (fid_interval = 1) : (fid_interval = 2);
 384
 385                 if (reqfid > data->currfid) {
 386                         if (data->currfid > LO_FID_TABLE_TOP) {
 387                                 if (write_new_fid(data,
 388                                                 data->currfid + fid_interval))
 389                                         return 1;
 390                         } else {
 391                                 if (write_new_fid
 392                                     (data,
 393                                      2 + convert_fid_to_vco_fid(data->currfid)))
 394                                         return 1;
 395                         }
 396                 } else {
 397                         if (write_new_fid(data, data->currfid - fid_interval))
 398                                 return 1;
 399                 }
 400
 401                 vcocurrfid = convert_fid_to_vco_fid(data->currfid);
 402                 vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
 403                     : vcoreqfid - vcocurrfid;
 404         }
 405
 406         if (write_new_fid(data, reqfid))
 407                 return 1;
 408
 409         if (query_current_values_with_pending_wait(data))
 410                 return 1;
 411
 412         if (data->currfid != reqfid) {
 413                 printk(KERN_ERR PFX
 414                         "ph2: mismatch, failed fid transition, "
 415                         "curr 0x%x, req 0x%x\n",
 416                         data->currfid, reqfid);
 417                 return 1;
 418         }
 419
 420         if (savevid != data->currvid) {
 421                 printk(KERN_ERR PFX "ph2: vid changed, save 0x%x, curr 0x%x\n",
 422                         savevid, data->currvid);
 423                 return 1;
 424         }
 425
 426         pr_debug("ph2 complete, currfid 0x%x, currvid 0x%x\n",
 427                 data->currfid, data->currvid);
 428
 429         return 0;
 430 }
 431
 432 /* Phase 3 - core voltage transition flow ... jump to the final vid. */
 433 static int core_voltage_post_transition(struct powernow_k8_data *data,
 434                 u32 reqvid)
 435 {
 436         u32 savefid = data->currfid;
 437         u32 savereqvid = reqvid;
 438
 439         pr_debug("ph3 (cpu%d): starting, currfid 0x%x, currvid 0x%x\n",
 440                 smp_processor_id(),
 441                 data->currfid, data->currvid);
 442
 443         if (reqvid != data->currvid) {
 444                 if (write_new_vid(data, reqvid))
 445                         return 1;
 446
 447                 if (savefid != data->currfid) {
 448                         printk(KERN_ERR PFX
 449                                "ph3: bad fid change, save 0x%x, curr 0x%x\n",
 450                                savefid, data->currfid);
 451                         return 1;
 452                 }
 453
 454                 if (data->currvid != reqvid) {
 455                         printk(KERN_ERR PFX
 456                                "ph3: failed vid transition\n, "
 457                                "req 0x%x, curr 0x%x",
 458                                reqvid, data->currvid);
 459                         return 1;
 460                 }
 461         }
 462
 463         if (query_current_values_with_pending_wait(data))
 464                 return 1;
 465
 466         if (savereqvid != data->currvid) {
 467                 pr_debug("ph3 failed, currvid 0x%x\n", data->currvid);
 468                 return 1;
 469         }
 470
 471         if (savefid != data->currfid) {
 472                 pr_debug("ph3 failed, currfid changed 0x%x\n",
 473                         data->currfid);
 474                 return 1;
 475         }
 476
 477         pr_debug("ph3 complete, currfid 0x%x, currvid 0x%x\n",
 478                 data->currfid, data->currvid);
 479
 480         return 0;
 481 }
 482
 483 static const struct x86_cpu_id powernow_k8_ids[] = {
 484         /* IO based frequency switching */
 485         { X86_VENDOR_AMD, 0xf },
 486         {}
 487 };
 488 MODULE_DEVICE_TABLE(x86cpu, powernow_k8_ids);
 489
 490 static void check_supported_cpu(void *_rc)
 491 {
 492         u32 eax, ebx, ecx, edx;
 493         int *rc = _rc;
 494
 495         *rc = -ENODEV;
 496
 497         eax = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
 498
 499         if ((eax & CPUID_XFAM) == CPUID_XFAM_K8) {
 500                 if (((eax & CPUID_USE_XFAM_XMOD) != CPUID_USE_XFAM_XMOD) ||
 501                     ((eax & CPUID_XMOD) > CPUID_XMOD_REV_MASK)) {
 502                         printk(KERN_INFO PFX
 503                                 "Processor cpuid %x not supported\n", eax);
 504                         return;
 505                 }
 506
 507                 eax = cpuid_eax(CPUID_GET_MAX_CAPABILITIES);
 508                 if (eax < CPUID_FREQ_VOLT_CAPABILITIES) {
 509                         printk(KERN_INFO PFX
 510                                "No frequency change capabilities detected\n");
 511                         return;
 512                 }
 513
 514                 cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
 515                 if ((edx & P_STATE_TRANSITION_CAPABLE)
 516                         != P_STATE_TRANSITION_CAPABLE) {
 517                         printk(KERN_INFO PFX
 518                                 "Power state transitions not supported\n");
 519                         return;
 520                 }
 521                 *rc = 0;
 522         }
 523 }
 524
 525 static int check_pst_table(struct powernow_k8_data *data, struct pst_s *pst,
 526                 u8 maxvid)
 527 {
 528         unsigned int j;
 529         u8 lastfid = 0xff;
 530
 531         for (j = 0; j < data->numps; j++) {
 532                 if (pst[j].vid > LEAST_VID) {
 533                         printk(KERN_ERR FW_BUG PFX "vid %d invalid : 0x%x\n",
 534                                j, pst[j].vid);
 535                         return -EINVAL;
 536                 }
 537                 if (pst[j].vid < data->rvo) {
 538                         /* vid + rvo >= 0 */
 539                         printk(KERN_ERR FW_BUG PFX "0 vid exceeded with pstate"
 540                                " %d\n", j);
 541                         return -ENODEV;
 542                 }
 543                 if (pst[j].vid < maxvid + data->rvo) {
 544                         /* vid + rvo >= maxvid */
 545                         printk(KERN_ERR FW_BUG PFX "maxvid exceeded with pstate"
 546                                " %d\n", j);
 547                         return -ENODEV;
 548                 }
 549                 if (pst[j].fid > MAX_FID) {
 550                         printk(KERN_ERR FW_BUG PFX "maxfid exceeded with pstate"
 551                                " %d\n", j);
 552                         return -ENODEV;
 553                 }
 554                 if (j && (pst[j].fid < HI_FID_TABLE_BOTTOM)) {
 555                         /* Only first fid is allowed to be in "low" range */
 556                         printk(KERN_ERR FW_BUG PFX "two low fids - %d : "
 557                                "0x%x\n", j, pst[j].fid);
 558                         return -EINVAL;
 559                 }
 560                 if (pst[j].fid < lastfid)
 561                         lastfid = pst[j].fid;
 562         }
 563         if (lastfid & 1) {
 564                 printk(KERN_ERR FW_BUG PFX "lastfid invalid\n");
 565                 return -EINVAL;
 566         }
 567         if (lastfid > LO_FID_TABLE_TOP)
 568                 printk(KERN_INFO FW_BUG PFX
 569                         "first fid not from lo freq table\n");
 570
 571         return 0;
 572 }
 573
 574 static void invalidate_entry(struct cpufreq_frequency_table *powernow_table,
 575                 unsigned int entry)
 576 {
 577         powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
 578 }
 579
 580 static void print_basics(struct powernow_k8_data *data)
 581 {
 582         int j;
 583         for (j = 0; j < data->numps; j++) {
 584                 if (data->powernow_table[j].frequency !=
 585                                 CPUFREQ_ENTRY_INVALID) {
 586                                 printk(KERN_INFO PFX
 587                                         "fid 0x%x (%d MHz), vid 0x%x\n",
 588                                         data->powernow_table[j].index & 0xff,
 589                                         data->powernow_table[j].frequency/1000,
 590                                         data->powernow_table[j].index >> 8);
 591                 }
 592         }
 593         if (data->batps)
 594                 printk(KERN_INFO PFX "Only %d pstates on battery\n",
 595                                 data->batps);
 596 }
 597
 598 static int fill_powernow_table(struct powernow_k8_data *data,
 599                 struct pst_s *pst, u8 maxvid)
 600 {
 601         struct cpufreq_frequency_table *powernow_table;
 602         unsigned int j;
 603
 604         if (data->batps) {
 605                 /* use ACPI support to get full speed on mains power */
 606                 printk(KERN_WARNING PFX
 607                         "Only %d pstates usable (use ACPI driver for full "
 608                         "range\n", data->batps);
 609                 data->numps = data->batps;
 610         }
 611
 612         for (j = 1; j < data->numps; j++) {
 613                 if (pst[j-1].fid >= pst[j].fid) {
 614                         printk(KERN_ERR PFX "PST out of sequence\n");
 615                         return -EINVAL;
 616                 }
 617         }
 618
 619         if (data->numps < 2) {
 620                 printk(KERN_ERR PFX "no p states to transition\n");
 621                 return -ENODEV;
 622         }
 623
 624         if (check_pst_table(data, pst, maxvid))
 625                 return -EINVAL;
 626
 627         powernow_table = kmalloc((sizeof(struct cpufreq_frequency_table)
 628                 * (data->numps + 1)), GFP_KERNEL);
 629         if (!powernow_table) {
 630                 printk(KERN_ERR PFX "powernow_table memory alloc failure\n");
 631                 return -ENOMEM;
 632         }
 633
 634         for (j = 0; j < data->numps; j++) {
 635                 int freq;
 636                 powernow_table[j].index = pst[j].fid; /* lower 8 bits */
 637                 powernow_table[j].index |= (pst[j].vid << 8); /* upper 8 bits */
 638                 freq = find_khz_freq_from_fid(pst[j].fid);
 639                 powernow_table[j].frequency = freq;
 640         }
 641         powernow_table[data->numps].frequency = CPUFREQ_TABLE_END;
 642         powernow_table[data->numps].index = 0;
 643
 644         if (query_current_values_with_pending_wait(data)) {
 645                 kfree(powernow_table);
 646                 return -EIO;
 647         }
 648
 649         pr_debug("cfid 0x%x, cvid 0x%x\n", data->currfid, data->currvid);
 650         data->powernow_table = powernow_table;
 651         if (cpumask_first(cpu_core_mask(data->cpu)) == data->cpu)
 652                 print_basics(data);
 653
 654         for (j = 0; j < data->numps; j++)
 655                 if ((pst[j].fid == data->currfid) &&
 656                     (pst[j].vid == data->currvid))
 657                         return 0;
 658
 659         pr_debug("currfid/vid do not match PST, ignoring\n");
 660         return 0;
 661 }
 662
 663 /* Find and validate the PSB/PST table in BIOS. */
 664 static int find_psb_table(struct powernow_k8_data *data)
 665 {
 666         struct psb_s *psb;
 667         unsigned int i;
 668         u32 mvs;
 669         u8 maxvid;
 670         u32 cpst = 0;
 671         u32 thiscpuid;
 672
 673         for (i = 0xc0000; i < 0xffff0; i += 0x10) {
 674                 /* Scan BIOS looking for the signature. */
 675                 /* It can not be at ffff0 - it is too big. */
 676
 677                 psb = phys_to_virt(i);
 678                 if (memcmp(psb, PSB_ID_STRING, PSB_ID_STRING_LEN) != 0)
 679                         continue;
 680
 681                 pr_debug("found PSB header at 0x%p\n", psb);
 682
 683                 pr_debug("table vers: 0x%x\n", psb->tableversion);
 684                 if (psb->tableversion != PSB_VERSION_1_4) {
 685                         printk(KERN_ERR FW_BUG PFX "PSB table is not v1.4\n");
 686                         return -ENODEV;
 687                 }
 688
 689                 pr_debug("flags: 0x%x\n", psb->flags1);
 690                 if (psb->flags1) {
 691                         printk(KERN_ERR FW_BUG PFX "unknown flags\n");
 692                         return -ENODEV;
 693                 }
 694
 695                 data->vstable = psb->vstable;
 696                 pr_debug("voltage stabilization time: %d(*20us)\n",
 697                                 data->vstable);
 698
 699                 pr_debug("flags2: 0x%x\n", psb->flags2);
 700                 data->rvo = psb->flags2 & 3;
 701                 data->irt = ((psb->flags2) >> 2) & 3;
 702                 mvs = ((psb->flags2) >> 4) & 3;
 703                 data->vidmvs = 1 << mvs;
 704                 data->batps = ((psb->flags2) >> 6) & 3;
 705
 706                 pr_debug("ramp voltage offset: %d\n", data->rvo);
 707                 pr_debug("isochronous relief time: %d\n", data->irt);
 708                 pr_debug("maximum voltage step: %d - 0x%x\n", mvs, data->vidmvs);
 709
 710                 pr_debug("numpst: 0x%x\n", psb->num_tables);
 711                 cpst = psb->num_tables;
 712                 if ((psb->cpuid == 0x00000fc0) ||
 713                     (psb->cpuid == 0x00000fe0)) {
 714                         thiscpuid = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
 715                         if ((thiscpuid == 0x00000fc0) ||
 716                             (thiscpuid == 0x00000fe0))
 717                                 cpst = 1;
 718                 }
 719                 if (cpst != 1) {
 720                         printk(KERN_ERR FW_BUG PFX "numpst must be 1\n");
 721                         return -ENODEV;
 722                 }
 723
 724                 data->plllock = psb->plllocktime;
 725                 pr_debug("plllocktime: 0x%x (units 1us)\n", psb->plllocktime);
 726                 pr_debug("maxfid: 0x%x\n", psb->maxfid);
 727                 pr_debug("maxvid: 0x%x\n", psb->maxvid);
 728                 maxvid = psb->maxvid;
 729
 730                 data->numps = psb->numps;
 731                 pr_debug("numpstates: 0x%x\n", data->numps);
 732                 return fill_powernow_table(data,
 733                                 (struct pst_s *)(psb+1), maxvid);
 734         }
 735         /*
 736          * If you see this message, complain to BIOS manufacturer. If
 737          * he tells you "we do not support Linux" or some similar
 738          * nonsense, remember that Windows 2000 uses the same legacy
 739          * mechanism that the old Linux PSB driver uses. Tell them it
 740          * is broken with Windows 2000.
 741          *
 742          * The reference to the AMD documentation is chapter 9 in the
 743          * BIOS and Kernel Developer's Guide, which is available on
 744          * www.amd.com
 745          */
 746         printk(KERN_ERR FW_BUG PFX "No PSB or ACPI _PSS objects\n");
 747         printk(KERN_ERR PFX "Make sure that your BIOS is up to date"
 748                 " and Cool'N'Quiet support is enabled in BIOS setup\n");
 749         return -ENODEV;
 750 }
 751
 752 static void powernow_k8_acpi_pst_values(struct powernow_k8_data *data,
 753                 unsigned int index)
 754 {
 755         u64 control;
 756
 757         if (!data->acpi_data.state_count)
 758                 return;
 759
 760         control = data->acpi_data.states[index].control;
 761         data->irt = (control >> IRT_SHIFT) & IRT_MASK;
 762         data->rvo = (control >> RVO_SHIFT) & RVO_MASK;
 763         data->exttype = (control >> EXT_TYPE_SHIFT) & EXT_TYPE_MASK;
 764         data->plllock = (control >> PLL_L_SHIFT) & PLL_L_MASK;
 765         data->vidmvs = 1 << ((control >> MVS_SHIFT) & MVS_MASK);
 766         data->vstable = (control >> VST_SHIFT) & VST_MASK;
 767 }
 768
 769 static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data)
 770 {
 771         struct cpufreq_frequency_table *powernow_table;
 772         int ret_val = -ENODEV;
 773         u64 control, status;
 774
 775         if (acpi_processor_register_performance(&data->acpi_data, data->cpu)) {
 776                 pr_debug("register performance failed: bad ACPI data\n");
 777                 return -EIO;
 778         }
 779
 780         /* verify the data contained in the ACPI structures */
 781         if (data->acpi_data.state_count <= 1) {
 782                 pr_debug("No ACPI P-States\n");
 783                 goto err_out;
 784         }
 785
 786         control = data->acpi_data.control_register.space_id;
 787         status = data->acpi_data.status_register.space_id;
 788
 789         if ((control != ACPI_ADR_SPACE_FIXED_HARDWARE) ||
 790             (status != ACPI_ADR_SPACE_FIXED_HARDWARE)) {
 791                 pr_debug("Invalid control/status registers (%llx - %llx)\n",
 792                         control, status);
 793                 goto err_out;
 794         }
 795
 796         /* fill in data->powernow_table */
 797         powernow_table = kmalloc((sizeof(struct cpufreq_frequency_table)
 798                 * (data->acpi_data.state_count + 1)), GFP_KERNEL);
 799         if (!powernow_table) {
 800                 pr_debug("powernow_table memory alloc failure\n");
 801                 goto err_out;
 802         }
 803
 804         /* fill in data */
 805         data->numps = data->acpi_data.state_count;
 806         powernow_k8_acpi_pst_values(data, 0);
 807
 808         ret_val = fill_powernow_table_fidvid(data, powernow_table);
 809         if (ret_val)
 810                 goto err_out_mem;
 811
 812         powernow_table[data->acpi_data.state_count].frequency =
 813                 CPUFREQ_TABLE_END;
 814         powernow_table[data->acpi_data.state_count].index = 0;
 815         data->powernow_table = powernow_table;
 816
 817         if (cpumask_first(cpu_core_mask(data->cpu)) == data->cpu)
 818                 print_basics(data);
 819
 820         /* notify BIOS that we exist */
 821         acpi_processor_notify_smm(THIS_MODULE);
 822
 823         if (!zalloc_cpumask_var(&data->acpi_data.shared_cpu_map, GFP_KERNEL)) {
 824                 printk(KERN_ERR PFX
 825                                 "unable to alloc powernow_k8_data cpumask\n");
 826                 ret_val = -ENOMEM;
 827                 goto err_out_mem;
 828         }
 829
 830         return 0;
 831
 832 err_out_mem:
 833         kfree(powernow_table);
 834
 835 err_out:
 836         acpi_processor_unregister_performance(&data->acpi_data, data->cpu);
 837
 838         /* data->acpi_data.state_count informs us at ->exit()
 839          * whether ACPI was used */
 840         data->acpi_data.state_count = 0;
 841
 842         return ret_val;
 843 }
 844
 845 static int fill_powernow_table_fidvid(struct powernow_k8_data *data,
 846                 struct cpufreq_frequency_table *powernow_table)
 847 {
 848         int i;
 849
 850         for (i = 0; i < data->acpi_data.state_count; i++) {
 851                 u32 fid;
 852                 u32 vid;
 853                 u32 freq, index;
 854                 u64 status, control;
 855
 856                 if (data->exttype) {
 857                         status =  data->acpi_data.states[i].status;
 858                         fid = status & EXT_FID_MASK;
 859                         vid = (status >> VID_SHIFT) & EXT_VID_MASK;
 860                 } else {
 861                         control =  data->acpi_data.states[i].control;
 862                         fid = control & FID_MASK;
 863                         vid = (control >> VID_SHIFT) & VID_MASK;
 864                 }
 865
 866                 pr_debug("   %d : fid 0x%x, vid 0x%x\n", i, fid, vid);
 867
 868                 index = fid | (vid<<8);
 869                 powernow_table[i].index = index;
 870
 871                 freq = find_khz_freq_from_fid(fid);
 872                 powernow_table[i].frequency = freq;
 873
 874                 /* verify frequency is OK */
 875                 if ((freq > (MAX_FREQ * 1000)) || (freq < (MIN_FREQ * 1000))) {
 876                         pr_debug("invalid freq %u kHz, ignoring\n", freq);
 877                         invalidate_entry(powernow_table, i);
 878                         continue;
 879                 }
 880
 881                 /* verify voltage is OK -
 882                  * BIOSs are using "off" to indicate invalid */
 883                 if (vid == VID_OFF) {
 884                         pr_debug("invalid vid %u, ignoring\n", vid);
 885                         invalidate_entry(powernow_table, i);
 886                         continue;
 887                 }
 888
 889                 if (freq != (data->acpi_data.states[i].core_frequency * 1000)) {
 890                         printk(KERN_INFO PFX "invalid freq entries "
 891                                 "%u kHz vs. %u kHz\n", freq,
 892                                 (unsigned int)
 893                                 (data->acpi_data.states[i].core_frequency
 894                                  * 1000));
 895                         invalidate_entry(powernow_table, i);
 896                         continue;
 897                 }
 898         }
 899         return 0;
 900 }
 901
 902 static void powernow_k8_cpu_exit_acpi(struct powernow_k8_data *data)
 903 {
 904         if (data->acpi_data.state_count)
 905                 acpi_processor_unregister_performance(&data->acpi_data,
 906                                 data->cpu);
 907         free_cpumask_var(data->acpi_data.shared_cpu_map);
 908 }
 909
 910 static int get_transition_latency(struct powernow_k8_data *data)
 911 {
 912         int max_latency = 0;
 913         int i;
 914         for (i = 0; i < data->acpi_data.state_count; i++) {
 915                 int cur_latency = data->acpi_data.states[i].transition_latency
 916                         + data->acpi_data.states[i].bus_master_latency;
 917                 if (cur_latency > max_latency)
 918                         max_latency = cur_latency;
 919         }
 920         if (max_latency == 0) {
 921                 pr_err(FW_WARN PFX "Invalid zero transition latency\n");
 922                 max_latency = 1;
 923         }
 924         /* value in usecs, needs to be in nanoseconds */
 925         return 1000 * max_latency;
 926 }
 927
 928 /* Take a frequency, and issue the fid/vid transition command */
 929 static int transition_frequency_fidvid(struct powernow_k8_data *data,
 930                 unsigned int index)
 931 {
 932         u32 fid = 0;
 933         u32 vid = 0;
 934         int res, i;
 935         struct cpufreq_freqs freqs;
 936
 937         pr_debug("cpu %d transition to index %u\n", smp_processor_id(), index);
 938
 939         /* fid/vid correctness check for k8 */
 940         /* fid are the lower 8 bits of the index we stored into
 941          * the cpufreq frequency table in find_psb_table, vid
 942          * are the upper 8 bits.
 943          */
 944         fid = data->powernow_table[index].index & 0xFF;
 945         vid = (data->powernow_table[index].index & 0xFF00) >> 8;
 946
 947         pr_debug("table matched fid 0x%x, giving vid 0x%x\n", fid, vid);
 948
 949         if (query_current_values_with_pending_wait(data))
 950                 return 1;
 951
 952         if ((data->currvid == vid) && (data->currfid == fid)) {
 953                 pr_debug("target matches current values (fid 0x%x, vid 0x%x)\n",
 954                         fid, vid);
 955                 return 0;
 956         }
 957
 958         pr_debug("cpu %d, changing to fid 0x%x, vid 0x%x\n",
 959                 smp_processor_id(), fid, vid);
 960         freqs.old = find_khz_freq_from_fid(data->currfid);
 961         freqs.new = find_khz_freq_from_fid(fid);
 962
 963         for_each_cpu(i, data->available_cores) {
 964                 freqs.cpu = i;
 965                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 966         }
 967
 968         res = transition_fid_vid(data, fid, vid);
 969         if (res)
 970                 return res;
 971
 972         freqs.new = find_khz_freq_from_fid(data->currfid);
 973
 974         for_each_cpu(i, data->available_cores) {
 975                 freqs.cpu = i;
 976                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 977         }
 978         return res;
 979 }
 980
 981 /* Driver entry point to switch to the target frequency */
 982 static int powernowk8_target(struct cpufreq_policy *pol,
 983                 unsigned targfreq, unsigned relation)
 984 {
 985         cpumask_var_t oldmask;
 986         struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
 987         u32 checkfid;
 988         u32 checkvid;
 989         unsigned int newstate;
 990         int ret = -EIO;
 991
 992         if (!data)
 993                 return -EINVAL;
 994
 995         checkfid = data->currfid;
 996         checkvid = data->currvid;
 997
 998         /* only run on specific CPU from here on. */
 999         /* This is poor form: use a workqueue or smp_call_function_single */
1000         if (!alloc_cpumask_var(&oldmask, GFP_KERNEL))
1001                 return -ENOMEM;
1002
1003         cpumask_copy(oldmask, tsk_cpus_allowed(current));
1004         set_cpus_allowed_ptr(current, cpumask_of(pol->cpu));
1005
1006         if (smp_processor_id() != pol->cpu) {
1007                 printk(KERN_ERR PFX "limiting to cpu %u failed\n", pol->cpu);
1008                 goto err_out;
1009         }
1010
1011         if (pending_bit_stuck()) {
1012                 printk(KERN_ERR PFX "failing targ, change pending bit set\n");
1013                 goto err_out;
1014         }
1015
1016         pr_debug("targ: cpu %d, %d kHz, min %d, max %d, relation %d\n",
1017                 pol->cpu, targfreq, pol->min, pol->max, relation);
1018
1019         if (query_current_values_with_pending_wait(data))
1020                 goto err_out;
1021
1022         pr_debug("targ: curr fid 0x%x, vid 0x%x\n",
1023                  data->currfid, data->currvid);
1024
1025         if ((checkvid != data->currvid) ||
1026             (checkfid != data->currfid)) {
1027                 pr_info(PFX
1028                        "error - out of sync, fix 0x%x 0x%x, vid 0x%x 0x%x\n",
1029                        checkfid, data->currfid,
1030                        checkvid, data->currvid);
1031         }
1032
1033         if (cpufreq_frequency_table_target(pol, data->powernow_table,
1034                                 targfreq, relation, &newstate))
1035                 goto err_out;
1036
1037         mutex_lock(&fidvid_mutex);
1038
1039         powernow_k8_acpi_pst_values(data, newstate);
1040
1041         ret = transition_frequency_fidvid(data, newstate);
1042
1043         if (ret) {
1044                 printk(KERN_ERR PFX "transition frequency failed\n");
1045                 ret = 1;
1046                 mutex_unlock(&fidvid_mutex);
1047                 goto err_out;
1048         }
1049         mutex_unlock(&fidvid_mutex);
1050
1051         pol->cur = find_khz_freq_from_fid(data->currfid);
1052         ret = 0;
1053
1054 err_out:
1055         set_cpus_allowed_ptr(current, oldmask);
1056         free_cpumask_var(oldmask);
1057         return ret;
1058 }
1059
1060 /* Driver entry point to verify the policy and range of frequencies */
1061 static int powernowk8_verify(struct cpufreq_policy *pol)
1062 {
1063         struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
1064
1065         if (!data)
1066                 return -EINVAL;
1067
1068         return cpufreq_frequency_table_verify(pol, data->powernow_table);
1069 }
1070
1071 struct init_on_cpu {
1072         struct powernow_k8_data *data;
1073         int rc;
1074 };
1075
1076 static void __cpuinit powernowk8_cpu_init_on_cpu(void *_init_on_cpu)
1077 {
1078         struct init_on_cpu *init_on_cpu = _init_on_cpu;
1079
1080         if (pending_bit_stuck()) {
1081                 printk(KERN_ERR PFX "failing init, change pending bit set\n");
1082                 init_on_cpu->rc = -ENODEV;
1083                 return;
1084         }
1085
1086         if (query_current_values_with_pending_wait(init_on_cpu->data)) {
1087                 init_on_cpu->rc = -ENODEV;
1088                 return;
1089         }
1090
1091         fidvid_msr_init();
1092
1093         init_on_cpu->rc = 0;
1094 }
1095
1096 static const char missing_pss_msg[] =
1097         KERN_ERR
1098         FW_BUG PFX "No compatible ACPI _PSS objects found.\n"
1099         FW_BUG PFX "First, make sure Cool'N'Quiet is enabled in the BIOS.\n"
1100         FW_BUG PFX "If that doesn't help, try upgrading your BIOS.\n";
1101
1102 /* per CPU init entry point to the driver */
1103 static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
1104 {
1105         struct powernow_k8_data *data;
1106         struct init_on_cpu init_on_cpu;
1107         int rc;
1108
1109         if (!cpu_online(pol->cpu))
1110                 return -ENODEV;
1111
1112         smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1);
1113         if (rc)
1114                 return -ENODEV;
1115
1116         data = kzalloc(sizeof(struct powernow_k8_data), GFP_KERNEL);
1117         if (!data) {
1118                 printk(KERN_ERR PFX "unable to alloc powernow_k8_data");
1119                 return -ENOMEM;
1120         }
1121
1122         data->cpu = pol->cpu;
1123
1124         if (powernow_k8_cpu_init_acpi(data)) {
1125                 /*
1126                  * Use the PSB BIOS structure. This is only available on
1127                  * an UP version, and is deprecated by AMD.
1128                  */
1129                 if (num_online_cpus() != 1) {
1130                         printk_once(missing_pss_msg);
1131                         goto err_out;
1132                 }
1133                 if (pol->cpu != 0) {
1134                         printk(KERN_ERR FW_BUG PFX "No ACPI _PSS objects for "
1135                                "CPU other than CPU0. Complain to your BIOS "
1136                                "vendor.\n");
1137                         goto err_out;
1138                 }
1139                 rc = find_psb_table(data);
1140                 if (rc)
1141                         goto err_out;
1142
1143                 /* Take a crude guess here.
1144                  * That guess was in microseconds, so multiply with 1000 */
1145                 pol->cpuinfo.transition_latency = (
1146                          ((data->rvo + 8) * data->vstable * VST_UNITS_20US) +
1147                          ((1 << data->irt) * 30)) * 1000;
1148         } else /* ACPI _PSS objects available */
1149                 pol->cpuinfo.transition_latency = get_transition_latency(data);
1150
1151         /* only run on specific CPU from here on */
1152         init_on_cpu.data = data;
1153         smp_call_function_single(data->cpu, powernowk8_cpu_init_on_cpu,
1154                                  &init_on_cpu, 1);
1155         rc = init_on_cpu.rc;
1156         if (rc != 0)
1157                 goto err_out_exit_acpi;
1158
1159         cpumask_copy(pol->cpus, cpu_core_mask(pol->cpu));
1160         data->available_cores = pol->cpus;
1161
1162         pol->cur = find_khz_freq_from_fid(data->currfid);
1163         pr_debug("policy current frequency %d kHz\n", pol->cur);
1164
1165         /* min/max the cpu is capable of */
1166         if (cpufreq_frequency_table_cpuinfo(pol, data->powernow_table)) {
1167                 printk(KERN_ERR FW_BUG PFX "invalid powernow_table\n");
1168                 powernow_k8_cpu_exit_acpi(data);
1169                 kfree(data->powernow_table);
1170                 kfree(data);
1171                 return -EINVAL;
1172         }
1173
1174         cpufreq_frequency_table_get_attr(data->powernow_table, pol->cpu);
1175
1176         pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n",
1177                  data->currfid, data->currvid);
1178
1179         per_cpu(powernow_data, pol->cpu) = data;
1180
1181         return 0;
1182
1183 err_out_exit_acpi:
1184         powernow_k8_cpu_exit_acpi(data);
1185
1186 err_out:
1187         kfree(data);
1188         return -ENODEV;
1189 }
1190
1191 static int __devexit powernowk8_cpu_exit(struct cpufreq_policy *pol)
1192 {
1193         struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
1194
1195         if (!data)
1196                 return -EINVAL;
1197
1198         powernow_k8_cpu_exit_acpi(data);
1199
1200         cpufreq_frequency_table_put_attr(pol->cpu);
1201
1202         kfree(data->powernow_table);
1203         kfree(data);
1204         per_cpu(powernow_data, pol->cpu) = NULL;
1205
1206         return 0;
1207 }
1208
1209 static void query_values_on_cpu(void *_err)
1210 {
1211         int *err = _err;
1212         struct powernow_k8_data *data = __this_cpu_read(powernow_data);
1213
1214         *err = query_current_values_with_pending_wait(data);
1215 }
1216
1217 static unsigned int powernowk8_get(unsigned int cpu)
1218 {
1219         struct powernow_k8_data *data = per_cpu(powernow_data, cpu);
1220         unsigned int khz = 0;
1221         int err;
1222
1223         if (!data)
1224                 return 0;
1225
1226         smp_call_function_single(cpu, query_values_on_cpu, &err, true);
1227         if (err)
1228                 goto out;
1229
1230         khz = find_khz_freq_from_fid(data->currfid);
1231
1232
1233 out:
1234         return khz;
1235 }
1236
1237 static struct freq_attr *powernow_k8_attr[] = {
1238         &cpufreq_freq_attr_scaling_available_freqs,
1239         NULL,
1240 };
1241
1242 static struct cpufreq_driver cpufreq_amd64_driver = {
1243         .verify         = powernowk8_verify,
1244         .target         = powernowk8_target,
1245         .bios_limit     = acpi_processor_get_bios_limit,
1246         .init           = powernowk8_cpu_init,
1247         .exit           = __devexit_p(powernowk8_cpu_exit),
1248         .get            = powernowk8_get,
1249         .name           = "powernow-k8",
1250         .owner          = THIS_MODULE,
1251         .attr           = powernow_k8_attr,
1252 };
1253
1254 /* driver entry point for init */
1255 static int __cpuinit powernowk8_init(void)
1256 {
1257         unsigned int i, supported_cpus = 0;
1258         int rv;
1259
1260         if (static_cpu_has(X86_FEATURE_HW_PSTATE)) {
1261                 pr_warn(PFX "this CPU is not supported anymore, using acpi-cpufreq instead.\n");
1262                 request_module("acpi-cpufreq");
1263                 return -ENODEV;
1264         }
1265
1266         if (!x86_match_cpu(powernow_k8_ids))
1267                 return -ENODEV;
1268
1269         for_each_online_cpu(i) {
1270                 int rc;
1271                 smp_call_function_single(i, check_supported_cpu, &rc, 1);
1272                 if (rc == 0)
1273                         supported_cpus++;
1274         }
1275
1276         if (supported_cpus != num_online_cpus())
1277                 return -ENODEV;
1278
1279         rv = cpufreq_register_driver(&cpufreq_amd64_driver);
1280
1281         if (!rv)
1282                 pr_info(PFX "Found %d %s (%d cpu cores) (" VERSION ")\n",
1283                         num_online_nodes(), boot_cpu_data.x86_model_id,
1284                         supported_cpus);
1285
1286         return rv;
1287 }
1288
1289 /* driver entry point for term */
1290 static void __exit powernowk8_exit(void)
1291 {
1292         pr_debug("exit\n");
1293
1294         cpufreq_unregister_driver(&cpufreq_amd64_driver);
1295 }
1296
1297 MODULE_AUTHOR("Paul Devriendt <paul.devriendt@amd.com> and "
1298                 "Mark Langsdorf <mark.langsdorf@amd.com>");
1299 MODULE_DESCRIPTION("AMD Athlon 64 and Opteron processor frequency driver.");
1300 MODULE_LICENSE("GPL");
1301
1302 late_initcall(powernowk8_init);
1303 module_exit(powernowk8_exit);