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 <herrmann.der.user@googlemail.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/io.h>
  39 #include <linux/delay.h>
  40
  41 #include <asm/msr.h>
  42 #include <asm/cpu_device_id.h>
  43
  44 #include <linux/acpi.h>
  45 #include <linux/mutex.h>
  46 #include <acpi/processor.h>
  47
  48 #define PFX "powernow-k8: "
  49 #define VERSION "version 2.20.00"
  50 #include "powernow-k8.h"
  51
  52 /* serialize freq changes  */
  53 static DEFINE_MUTEX(fidvid_mutex);
  54
  55 static DEFINE_PER_CPU(struct powernow_k8_data *, powernow_data);
  56
  57 static struct cpufreq_driver cpufreq_amd64_driver;
  58
  59 #ifndef CONFIG_SMP
  60 static inline const struct cpumask *cpu_core_mask(int cpu)
  61 {
  62         return cpumask_of(0);
  63 }
  64 #endif
  65
  66 /* Return a frequency in MHz, given an input fid */
  67 static u32 find_freq_from_fid(u32 fid)
  68 {
  69         return 800 + (fid * 100);
  70 }
  71
  72 /* Return a frequency in KHz, given an input fid */
  73 static u32 find_khz_freq_from_fid(u32 fid)
  74 {
  75         return 1000 * find_freq_from_fid(fid);
  76 }
  77
  78 /* Return the vco fid for an input fid
  79  *
  80  * Each "low" fid has corresponding "high" fid, and you can get to "low" fids
  81  * only from corresponding high fids. This returns "high" fid corresponding to
  82  * "low" one.
  83  */
  84 static u32 convert_fid_to_vco_fid(u32 fid)
  85 {
  86         if (fid < HI_FID_TABLE_BOTTOM)
  87                 return 8 + (2 * fid);
  88         else
  89                 return fid;
  90 }
  91
  92 /*
  93  * Return 1 if the pending bit is set. Unless we just instructed the processor
  94  * to transition to a new state, seeing this bit set is really bad news.
  95  */
  96 static int pending_bit_stuck(void)
  97 {
  98         u32 lo, hi;
  99
 100         rdmsr(MSR_FIDVID_STATUS, lo, hi);
 101         return lo & MSR_S_LO_CHANGE_PENDING ? 1 : 0;
 102 }
 103
 104 /*
 105  * Update the global current fid / vid values from the status msr.
 106  * Returns 1 on error.
 107  */
 108 static int query_current_values_with_pending_wait(struct powernow_k8_data *data)
 109 {
 110         u32 lo, hi;
 111         u32 i = 0;
 112
 113         do {
 114                 if (i++ > 10000) {
 115                         pr_debug("detected change pending stuck\n");
 116                         return 1;
 117                 }
 118                 rdmsr(MSR_FIDVID_STATUS, lo, hi);
 119         } while (lo & MSR_S_LO_CHANGE_PENDING);
 120
 121         data->currvid = hi & MSR_S_HI_CURRENT_VID;
 122         data->currfid = lo & MSR_S_LO_CURRENT_FID;
 123
 124         return 0;
 125 }
 126
 127 /* the isochronous relief time */
 128 static void count_off_irt(struct powernow_k8_data *data)
 129 {
 130         udelay((1 << data->irt) * 10);
 131         return;
 132 }
 133
 134 /* the voltage stabilization time */
 135 static void count_off_vst(struct powernow_k8_data *data)
 136 {
 137         udelay(data->vstable * VST_UNITS_20US);
 138         return;
 139 }
 140
 141 /* need to init the control msr to a safe value (for each cpu) */
 142 static void fidvid_msr_init(void)
 143 {
 144         u32 lo, hi;
 145         u8 fid, vid;
 146
 147         rdmsr(MSR_FIDVID_STATUS, lo, hi);
 148         vid = hi & MSR_S_HI_CURRENT_VID;
 149         fid = lo & MSR_S_LO_CURRENT_FID;
 150         lo = fid | (vid << MSR_C_LO_VID_SHIFT);
 151         hi = MSR_C_HI_STP_GNT_BENIGN;
 152         pr_debug("cpu%d, init lo 0x%x, hi 0x%x\n", smp_processor_id(), lo, hi);
 153         wrmsr(MSR_FIDVID_CTL, lo, hi);
 154 }
 155
 156 /* write the new fid value along with the other control fields to the msr */
 157 static int write_new_fid(struct powernow_k8_data *data, u32 fid)
 158 {
 159         u32 lo;
 160         u32 savevid = data->currvid;
 161         u32 i = 0;
 162
 163         if ((fid & INVALID_FID_MASK) || (data->currvid & INVALID_VID_MASK)) {
 164                 printk(KERN_ERR PFX "internal error - overflow on fid write\n");
 165                 return 1;
 166         }
 167
 168         lo = fid;
 169         lo |= (data->currvid << MSR_C_LO_VID_SHIFT);
 170         lo |= MSR_C_LO_INIT_FID_VID;
 171
 172         pr_debug("writing fid 0x%x, lo 0x%x, hi 0x%x\n",
 173                 fid, lo, data->plllock * PLL_LOCK_CONVERSION);
 174
 175         do {
 176                 wrmsr(MSR_FIDVID_CTL, lo, data->plllock * PLL_LOCK_CONVERSION);
 177                 if (i++ > 100) {
 178                         printk(KERN_ERR PFX
 179                                 "Hardware error - pending bit very stuck - "
 180                                 "no further pstate changes possible\n");
 181                         return 1;
 182                 }
 183         } while (query_current_values_with_pending_wait(data));
 184
 185         count_off_irt(data);
 186
 187         if (savevid != data->currvid) {
 188                 printk(KERN_ERR PFX
 189                         "vid change on fid trans, old 0x%x, new 0x%x\n",
 190                         savevid, data->currvid);
 191                 return 1;
 192         }
 193
 194         if (fid != data->currfid) {
 195                 printk(KERN_ERR PFX
 196                         "fid trans failed, fid 0x%x, curr 0x%x\n", fid,
 197                         data->currfid);
 198                 return 1;
 199         }
 200
 201         return 0;
 202 }
 203
 204 /* Write a new vid to the hardware */
 205 static int write_new_vid(struct powernow_k8_data *data, u32 vid)
 206 {
 207         u32 lo;
 208         u32 savefid = data->currfid;
 209         int i = 0;
 210
 211         if ((data->currfid & INVALID_FID_MASK) || (vid & INVALID_VID_MASK)) {
 212                 printk(KERN_ERR PFX "internal error - overflow on vid write\n");
 213                 return 1;
 214         }
 215
 216         lo = data->currfid;
 217         lo |= (vid << MSR_C_LO_VID_SHIFT);
 218         lo |= MSR_C_LO_INIT_FID_VID;
 219
 220         pr_debug("writing vid 0x%x, lo 0x%x, hi 0x%x\n",
 221                 vid, lo, STOP_GRANT_5NS);
 222
 223         do {
 224                 wrmsr(MSR_FIDVID_CTL, lo, STOP_GRANT_5NS);
 225                 if (i++ > 100) {
 226                         printk(KERN_ERR PFX "internal error - pending bit "
 227                                         "very stuck - no further pstate "
 228                                         "changes possible\n");
 229                         return 1;
 230                 }
 231         } while (query_current_values_with_pending_wait(data));
 232
 233         if (savefid != data->currfid) {
 234                 printk(KERN_ERR PFX "fid changed on vid trans, old "
 235                         "0x%x new 0x%x\n",
 236                        savefid, data->currfid);
 237                 return 1;
 238         }
 239
 240         if (vid != data->currvid) {
 241                 printk(KERN_ERR PFX "vid trans failed, vid 0x%x, "
 242                                 "curr 0x%x\n",
 243                                 vid, data->currvid);
 244                 return 1;
 245         }
 246
 247         return 0;
 248 }
 249
 250 /*
 251  * Reduce the vid by the max of step or reqvid.
 252  * Decreasing vid codes represent increasing voltages:
 253  * vid of 0 is 1.550V, vid of 0x1e is 0.800V, vid of VID_OFF is off.
 254  */
 255 static int decrease_vid_code_by_step(struct powernow_k8_data *data,
 256                 u32 reqvid, u32 step)
 257 {
 258         if ((data->currvid - reqvid) > step)
 259                 reqvid = data->currvid - step;
 260
 261         if (write_new_vid(data, reqvid))
 262                 return 1;
 263
 264         count_off_vst(data);
 265
 266         return 0;
 267 }
 268
 269 /* Change Opteron/Athlon64 fid and vid, by the 3 phases. */
 270 static int transition_fid_vid(struct powernow_k8_data *data,
 271                 u32 reqfid, u32 reqvid)
 272 {
 273         if (core_voltage_pre_transition(data, reqvid, reqfid))
 274                 return 1;
 275
 276         if (core_frequency_transition(data, reqfid))
 277                 return 1;
 278
 279         if (core_voltage_post_transition(data, reqvid))
 280                 return 1;
 281
 282         if (query_current_values_with_pending_wait(data))
 283                 return 1;
 284
 285         if ((reqfid != data->currfid) || (reqvid != data->currvid)) {
 286                 printk(KERN_ERR PFX "failed (cpu%d): req 0x%x 0x%x, "
 287                                 "curr 0x%x 0x%x\n",
 288                                 smp_processor_id(),
 289                                 reqfid, reqvid, data->currfid, data->currvid);
 290                 return 1;
 291         }
 292
 293         pr_debug("transitioned (cpu%d): new fid 0x%x, vid 0x%x\n",
 294                 smp_processor_id(), data->currfid, data->currvid);
 295
 296         return 0;
 297 }
 298
 299 /* Phase 1 - core voltage transition ... setup voltage */
 300 static int core_voltage_pre_transition(struct powernow_k8_data *data,
 301                 u32 reqvid, u32 reqfid)
 302 {
 303         u32 rvosteps = data->rvo;
 304         u32 savefid = data->currfid;
 305         u32 maxvid, lo, rvomult = 1;
 306
 307         pr_debug("ph1 (cpu%d): start, currfid 0x%x, currvid 0x%x, "
 308                 "reqvid 0x%x, rvo 0x%x\n",
 309                 smp_processor_id(),
 310                 data->currfid, data->currvid, reqvid, data->rvo);
 311
 312         if ((savefid < LO_FID_TABLE_TOP) && (reqfid < LO_FID_TABLE_TOP))
 313                 rvomult = 2;
 314         rvosteps *= rvomult;
 315         rdmsr(MSR_FIDVID_STATUS, lo, maxvid);
 316         maxvid = 0x1f & (maxvid >> 16);
 317         pr_debug("ph1 maxvid=0x%x\n", maxvid);
 318         if (reqvid < maxvid) /* lower numbers are higher voltages */
 319                 reqvid = maxvid;
 320
 321         while (data->currvid > reqvid) {
 322                 pr_debug("ph1: curr 0x%x, req vid 0x%x\n",
 323                         data->currvid, reqvid);
 324                 if (decrease_vid_code_by_step(data, reqvid, data->vidmvs))
 325                         return 1;
 326         }
 327
 328         while ((rvosteps > 0) &&
 329                         ((rvomult * data->rvo + data->currvid) > reqvid)) {
 330                 if (data->currvid == maxvid) {
 331                         rvosteps = 0;
 332                 } else {
 333                         pr_debug("ph1: changing vid for rvo, req 0x%x\n",
 334                                 data->currvid - 1);
 335                         if (decrease_vid_code_by_step(data, data->currvid-1, 1))
 336                                 return 1;
 337                         rvosteps--;
 338                 }
 339         }
 340
 341         if (query_current_values_with_pending_wait(data))
 342                 return 1;
 343
 344         if (savefid != data->currfid) {
 345                 printk(KERN_ERR PFX "ph1 err, currfid changed 0x%x\n",
 346                                 data->currfid);
 347                 return 1;
 348         }
 349
 350         pr_debug("ph1 complete, currfid 0x%x, currvid 0x%x\n",
 351                 data->currfid, data->currvid);
 352
 353         return 0;
 354 }
 355
 356 /* Phase 2 - core frequency transition */
 357 static int core_frequency_transition(struct powernow_k8_data *data, u32 reqfid)
 358 {
 359         u32 vcoreqfid, vcocurrfid, vcofiddiff;
 360         u32 fid_interval, savevid = data->currvid;
 361
 362         if (data->currfid == reqfid) {
 363                 printk(KERN_ERR PFX "ph2 null fid transition 0x%x\n",
 364                                 data->currfid);
 365                 return 0;
 366         }
 367
 368         pr_debug("ph2 (cpu%d): starting, currfid 0x%x, currvid 0x%x, "
 369                 "reqfid 0x%x\n",
 370                 smp_processor_id(),
 371                 data->currfid, data->currvid, reqfid);
 372
 373         vcoreqfid = convert_fid_to_vco_fid(reqfid);
 374         vcocurrfid = convert_fid_to_vco_fid(data->currfid);
 375         vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
 376             : vcoreqfid - vcocurrfid;
 377
 378         if ((reqfid <= LO_FID_TABLE_TOP) && (data->currfid <= LO_FID_TABLE_TOP))
 379                 vcofiddiff = 0;
 380
 381         while (vcofiddiff > 2) {
 382                 (data->currfid & 1) ? (fid_interval = 1) : (fid_interval = 2);
 383
 384                 if (reqfid > data->currfid) {
 385                         if (data->currfid > LO_FID_TABLE_TOP) {
 386                                 if (write_new_fid(data,
 387                                                 data->currfid + fid_interval))
 388                                         return 1;
 389                         } else {
 390                                 if (write_new_fid
 391                                     (data,
 392                                      2 + convert_fid_to_vco_fid(data->currfid)))
 393                                         return 1;
 394                         }
 395                 } else {
 396                         if (write_new_fid(data, data->currfid - fid_interval))
 397                                 return 1;
 398                 }
 399
 400                 vcocurrfid = convert_fid_to_vco_fid(data->currfid);
 401                 vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
 402                     : vcoreqfid - vcocurrfid;
 403         }
 404
 405         if (write_new_fid(data, reqfid))
 406                 return 1;
 407
 408         if (query_current_values_with_pending_wait(data))
 409                 return 1;
 410
 411         if (data->currfid != reqfid) {
 412                 printk(KERN_ERR PFX
 413                         "ph2: mismatch, failed fid transition, "
 414                         "curr 0x%x, req 0x%x\n",
 415                         data->currfid, reqfid);
 416                 return 1;
 417         }
 418
 419         if (savevid != data->currvid) {
 420                 printk(KERN_ERR PFX "ph2: vid changed, save 0x%x, curr 0x%x\n",
 421                         savevid, data->currvid);
 422                 return 1;
 423         }
 424
 425         pr_debug("ph2 complete, currfid 0x%x, currvid 0x%x\n",
 426                 data->currfid, data->currvid);
 427
 428         return 0;
 429 }
 430
 431 /* Phase 3 - core voltage transition flow ... jump to the final vid. */
 432 static int core_voltage_post_transition(struct powernow_k8_data *data,
 433                 u32 reqvid)
 434 {
 435         u32 savefid = data->currfid;
 436         u32 savereqvid = reqvid;
 437
 438         pr_debug("ph3 (cpu%d): starting, currfid 0x%x, currvid 0x%x\n",
 439                 smp_processor_id(),
 440                 data->currfid, data->currvid);
 441
 442         if (reqvid != data->currvid) {
 443                 if (write_new_vid(data, reqvid))
 444                         return 1;
 445
 446                 if (savefid != data->currfid) {
 447                         printk(KERN_ERR PFX
 448                                "ph3: bad fid change, save 0x%x, curr 0x%x\n",
 449                                savefid, data->currfid);
 450                         return 1;
 451                 }
 452
 453                 if (data->currvid != reqvid) {
 454                         printk(KERN_ERR PFX
 455                                "ph3: failed vid transition\n, "
 456                                "req 0x%x, curr 0x%x",
 457                                reqvid, data->currvid);
 458                         return 1;
 459                 }
 460         }
 461
 462         if (query_current_values_with_pending_wait(data))
 463                 return 1;
 464
 465         if (savereqvid != data->currvid) {
 466                 pr_debug("ph3 failed, currvid 0x%x\n", data->currvid);
 467                 return 1;
 468         }
 469
 470         if (savefid != data->currfid) {
 471                 pr_debug("ph3 failed, currfid changed 0x%x\n",
 472                         data->currfid);
 473                 return 1;
 474         }
 475
 476         pr_debug("ph3 complete, currfid 0x%x, currvid 0x%x\n",
 477                 data->currfid, data->currvid);
 478
 479         return 0;
 480 }
 481
 482 static const struct x86_cpu_id powernow_k8_ids[] = {
 483         /* IO based frequency switching */
 484         { X86_VENDOR_AMD, 0xf },
 485         {}
 486 };
 487 MODULE_DEVICE_TABLE(x86cpu, powernow_k8_ids);
 488
 489 static void check_supported_cpu(void *_rc)
 490 {
 491         u32 eax, ebx, ecx, edx;
 492         int *rc = _rc;
 493
 494         *rc = -ENODEV;
 495
 496         eax = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
 497
 498         if ((eax & CPUID_XFAM) == CPUID_XFAM_K8) {
 499                 if (((eax & CPUID_USE_XFAM_XMOD) != CPUID_USE_XFAM_XMOD) ||
 500                     ((eax & CPUID_XMOD) > CPUID_XMOD_REV_MASK)) {
 501                         printk(KERN_INFO PFX
 502                                 "Processor cpuid %x not supported\n", eax);
 503                         return;
 504                 }
 505
 506                 eax = cpuid_eax(CPUID_GET_MAX_CAPABILITIES);
 507                 if (eax < CPUID_FREQ_VOLT_CAPABILITIES) {
 508                         printk(KERN_INFO PFX
 509                                "No frequency change capabilities detected\n");
 510                         return;
 511                 }
 512
 513                 cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
 514                 if ((edx & P_STATE_TRANSITION_CAPABLE)
 515                         != P_STATE_TRANSITION_CAPABLE) {
 516                         printk(KERN_INFO PFX
 517                                 "Power state transitions not supported\n");
 518                         return;
 519                 }
 520                 *rc = 0;
 521         }
 522 }
 523
 524 static int check_pst_table(struct powernow_k8_data *data, struct pst_s *pst,
 525                 u8 maxvid)
 526 {
 527         unsigned int j;
 528         u8 lastfid = 0xff;
 529
 530         for (j = 0; j < data->numps; j++) {
 531                 if (pst[j].vid > LEAST_VID) {
 532                         printk(KERN_ERR FW_BUG PFX "vid %d invalid : 0x%x\n",
 533                                j, pst[j].vid);
 534                         return -EINVAL;
 535                 }
 536                 if (pst[j].vid < data->rvo) {
 537                         /* vid + rvo >= 0 */
 538                         printk(KERN_ERR FW_BUG PFX "0 vid exceeded with pstate"
 539                                " %d\n", j);
 540                         return -ENODEV;
 541                 }
 542                 if (pst[j].vid < maxvid + data->rvo) {
 543                         /* vid + rvo >= maxvid */
 544                         printk(KERN_ERR FW_BUG PFX "maxvid exceeded with pstate"
 545                                " %d\n", j);
 546                         return -ENODEV;
 547                 }
 548                 if (pst[j].fid > MAX_FID) {
 549                         printk(KERN_ERR FW_BUG PFX "maxfid exceeded with pstate"
 550                                " %d\n", j);
 551                         return -ENODEV;
 552                 }
 553                 if (j && (pst[j].fid < HI_FID_TABLE_BOTTOM)) {
 554                         /* Only first fid is allowed to be in "low" range */
 555                         printk(KERN_ERR FW_BUG PFX "two low fids - %d : "
 556                                "0x%x\n", j, pst[j].fid);
 557                         return -EINVAL;
 558                 }
 559                 if (pst[j].fid < lastfid)
 560                         lastfid = pst[j].fid;
 561         }
 562         if (lastfid & 1) {
 563                 printk(KERN_ERR FW_BUG PFX "lastfid invalid\n");
 564                 return -EINVAL;
 565         }
 566         if (lastfid > LO_FID_TABLE_TOP)
 567                 printk(KERN_INFO FW_BUG PFX
 568                         "first fid not from lo freq table\n");
 569
 570         return 0;
 571 }
 572
 573 static void invalidate_entry(struct cpufreq_frequency_table *powernow_table,
 574                 unsigned int entry)
 575 {
 576         powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
 577 }
 578
 579 static void print_basics(struct powernow_k8_data *data)
 580 {
 581         int j;
 582         for (j = 0; j < data->numps; j++) {
 583                 if (data->powernow_table[j].frequency !=
 584                                 CPUFREQ_ENTRY_INVALID) {
 585                                 printk(KERN_INFO PFX
 586                                         "fid 0x%x (%d MHz), vid 0x%x\n",
 587                                         data->powernow_table[j].index & 0xff,
 588                                         data->powernow_table[j].frequency/1000,
 589                                         data->powernow_table[j].index >> 8);
 590                 }
 591         }
 592         if (data->batps)
 593                 printk(KERN_INFO PFX "Only %d pstates on battery\n",
 594                                 data->batps);
 595 }
 596
 597 static int fill_powernow_table(struct powernow_k8_data *data,
 598                 struct pst_s *pst, u8 maxvid)
 599 {
 600         struct cpufreq_frequency_table *powernow_table;
 601         unsigned int j;
 602
 603         if (data->batps) {
 604                 /* use ACPI support to get full speed on mains power */
 605                 printk(KERN_WARNING PFX
 606                         "Only %d pstates usable (use ACPI driver for full "
 607                         "range\n", data->batps);
 608                 data->numps = data->batps;
 609         }
 610
 611         for (j = 1; j < data->numps; j++) {
 612                 if (pst[j-1].fid >= pst[j].fid) {
 613                         printk(KERN_ERR PFX "PST out of sequence\n");
 614                         return -EINVAL;
 615                 }
 616         }
 617
 618         if (data->numps < 2) {
 619                 printk(KERN_ERR PFX "no p states to transition\n");
 620                 return -ENODEV;
 621         }
 622
 623         if (check_pst_table(data, pst, maxvid))
 624                 return -EINVAL;
 625
 626         powernow_table = kmalloc((sizeof(struct cpufreq_frequency_table)
 627                 * (data->numps + 1)), GFP_KERNEL);
 628         if (!powernow_table) {
 629                 printk(KERN_ERR PFX "powernow_table memory alloc failure\n");
 630                 return -ENOMEM;
 631         }
 632
 633         for (j = 0; j < data->numps; j++) {
 634                 int freq;
 635                 powernow_table[j].index = pst[j].fid; /* lower 8 bits */
 636                 powernow_table[j].index |= (pst[j].vid << 8); /* upper 8 bits */
 637                 freq = find_khz_freq_from_fid(pst[j].fid);
 638                 powernow_table[j].frequency = freq;
 639         }
 640         powernow_table[data->numps].frequency = CPUFREQ_TABLE_END;
 641         powernow_table[data->numps].index = 0;
 642
 643         if (query_current_values_with_pending_wait(data)) {
 644                 kfree(powernow_table);
 645                 return -EIO;
 646         }
 647
 648         pr_debug("cfid 0x%x, cvid 0x%x\n", data->currfid, data->currvid);
 649         data->powernow_table = powernow_table;
 650         if (cpumask_first(cpu_core_mask(data->cpu)) == data->cpu)
 651                 print_basics(data);
 652
 653         for (j = 0; j < data->numps; j++)
 654                 if ((pst[j].fid == data->currfid) &&
 655                     (pst[j].vid == data->currvid))
 656                         return 0;
 657
 658         pr_debug("currfid/vid do not match PST, ignoring\n");
 659         return 0;
 660 }
 661
 662 /* Find and validate the PSB/PST table in BIOS. */
 663 static int find_psb_table(struct powernow_k8_data *data)
 664 {
 665         struct psb_s *psb;
 666         unsigned int i;
 667         u32 mvs;
 668         u8 maxvid;
 669         u32 cpst = 0;
 670         u32 thiscpuid;
 671
 672         for (i = 0xc0000; i < 0xffff0; i += 0x10) {
 673                 /* Scan BIOS looking for the signature. */
 674                 /* It can not be at ffff0 - it is too big. */
 675
 676                 psb = phys_to_virt(i);
 677                 if (memcmp(psb, PSB_ID_STRING, PSB_ID_STRING_LEN) != 0)
 678                         continue;
 679
 680                 pr_debug("found PSB header at 0x%p\n", psb);
 681
 682                 pr_debug("table vers: 0x%x\n", psb->tableversion);
 683                 if (psb->tableversion != PSB_VERSION_1_4) {
 684                         printk(KERN_ERR FW_BUG PFX "PSB table is not v1.4\n");
 685                         return -ENODEV;
 686                 }
 687
 688                 pr_debug("flags: 0x%x\n", psb->flags1);
 689                 if (psb->flags1) {
 690                         printk(KERN_ERR FW_BUG PFX "unknown flags\n");
 691                         return -ENODEV;
 692                 }
 693
 694                 data->vstable = psb->vstable;
 695                 pr_debug("voltage stabilization time: %d(*20us)\n",
 696                                 data->vstable);
 697
 698                 pr_debug("flags2: 0x%x\n", psb->flags2);
 699                 data->rvo = psb->flags2 & 3;
 700                 data->irt = ((psb->flags2) >> 2) & 3;
 701                 mvs = ((psb->flags2) >> 4) & 3;
 702                 data->vidmvs = 1 << mvs;
 703                 data->batps = ((psb->flags2) >> 6) & 3;
 704
 705                 pr_debug("ramp voltage offset: %d\n", data->rvo);
 706                 pr_debug("isochronous relief time: %d\n", data->irt);
 707                 pr_debug("maximum voltage step: %d - 0x%x\n", mvs, data->vidmvs);
 708
 709                 pr_debug("numpst: 0x%x\n", psb->num_tables);
 710                 cpst = psb->num_tables;
 711                 if ((psb->cpuid == 0x00000fc0) ||
 712                     (psb->cpuid == 0x00000fe0)) {
 713                         thiscpuid = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
 714                         if ((thiscpuid == 0x00000fc0) ||
 715                             (thiscpuid == 0x00000fe0))
 716                                 cpst = 1;
 717                 }
 718                 if (cpst != 1) {
 719                         printk(KERN_ERR FW_BUG PFX "numpst must be 1\n");
 720                         return -ENODEV;
 721                 }
 722
 723                 data->plllock = psb->plllocktime;
 724                 pr_debug("plllocktime: 0x%x (units 1us)\n", psb->plllocktime);
 725                 pr_debug("maxfid: 0x%x\n", psb->maxfid);
 726                 pr_debug("maxvid: 0x%x\n", psb->maxvid);
 727                 maxvid = psb->maxvid;
 728
 729                 data->numps = psb->numps;
 730                 pr_debug("numpstates: 0x%x\n", data->numps);
 731                 return fill_powernow_table(data,
 732                                 (struct pst_s *)(psb+1), maxvid);
 733         }
 734         /*
 735          * If you see this message, complain to BIOS manufacturer. If
 736          * he tells you "we do not support Linux" or some similar
 737          * nonsense, remember that Windows 2000 uses the same legacy
 738          * mechanism that the old Linux PSB driver uses. Tell them it
 739          * is broken with Windows 2000.
 740          *
 741          * The reference to the AMD documentation is chapter 9 in the
 742          * BIOS and Kernel Developer's Guide, which is available on
 743          * www.amd.com
 744          */
 745         printk(KERN_ERR FW_BUG PFX "No PSB or ACPI _PSS objects\n");
 746         printk(KERN_ERR PFX "Make sure that your BIOS is up to date"
 747                 " and Cool'N'Quiet support is enabled in BIOS setup\n");
 748         return -ENODEV;
 749 }
 750
 751 static void powernow_k8_acpi_pst_values(struct powernow_k8_data *data,
 752                 unsigned int index)
 753 {
 754         u64 control;
 755
 756         if (!data->acpi_data.state_count)
 757                 return;
 758
 759         control = data->acpi_data.states[index].control;
 760         data->irt = (control >> IRT_SHIFT) & IRT_MASK;
 761         data->rvo = (control >> RVO_SHIFT) & RVO_MASK;
 762         data->exttype = (control >> EXT_TYPE_SHIFT) & EXT_TYPE_MASK;
 763         data->plllock = (control >> PLL_L_SHIFT) & PLL_L_MASK;
 764         data->vidmvs = 1 << ((control >> MVS_SHIFT) & MVS_MASK);
 765         data->vstable = (control >> VST_SHIFT) & VST_MASK;
 766 }
 767
 768 static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data)
 769 {
 770         struct cpufreq_frequency_table *powernow_table;
 771         int ret_val = -ENODEV;
 772         u64 control, status;
 773
 774         if (acpi_processor_register_performance(&data->acpi_data, data->cpu)) {
 775                 pr_debug("register performance failed: bad ACPI data\n");
 776                 return -EIO;
 777         }
 778
 779         /* verify the data contained in the ACPI structures */
 780         if (data->acpi_data.state_count <= 1) {
 781                 pr_debug("No ACPI P-States\n");
 782                 goto err_out;
 783         }
 784
 785         control = data->acpi_data.control_register.space_id;
 786         status = data->acpi_data.status_register.space_id;
 787
 788         if ((control != ACPI_ADR_SPACE_FIXED_HARDWARE) ||
 789             (status != ACPI_ADR_SPACE_FIXED_HARDWARE)) {
 790                 pr_debug("Invalid control/status registers (%llx - %llx)\n",
 791                         control, status);
 792                 goto err_out;
 793         }
 794
 795         /* fill in data->powernow_table */
 796         powernow_table = kmalloc((sizeof(struct cpufreq_frequency_table)
 797                 * (data->acpi_data.state_count + 1)), GFP_KERNEL);
 798         if (!powernow_table) {
 799                 pr_debug("powernow_table memory alloc failure\n");
 800                 goto err_out;
 801         }
 802
 803         /* fill in data */
 804         data->numps = data->acpi_data.state_count;
 805         powernow_k8_acpi_pst_values(data, 0);
 806
 807         ret_val = fill_powernow_table_fidvid(data, powernow_table);
 808         if (ret_val)
 809                 goto err_out_mem;
 810
 811         powernow_table[data->acpi_data.state_count].frequency =
 812                 CPUFREQ_TABLE_END;
 813         powernow_table[data->acpi_data.state_count].index = 0;
 814         data->powernow_table = powernow_table;
 815
 816         if (cpumask_first(cpu_core_mask(data->cpu)) == data->cpu)
 817                 print_basics(data);
 818
 819         /* notify BIOS that we exist */
 820         acpi_processor_notify_smm(THIS_MODULE);
 821
 822         if (!zalloc_cpumask_var(&data->acpi_data.shared_cpu_map, GFP_KERNEL)) {
 823                 printk(KERN_ERR PFX
 824                                 "unable to alloc powernow_k8_data cpumask\n");
 825                 ret_val = -ENOMEM;
 826                 goto err_out_mem;
 827         }
 828
 829         return 0;
 830
 831 err_out_mem:
 832         kfree(powernow_table);
 833
 834 err_out:
 835         acpi_processor_unregister_performance(&data->acpi_data, data->cpu);
 836
 837         /* data->acpi_data.state_count informs us at ->exit()
 838          * whether ACPI was used */
 839         data->acpi_data.state_count = 0;
 840
 841         return ret_val;
 842 }
 843
 844 static int fill_powernow_table_fidvid(struct powernow_k8_data *data,
 845                 struct cpufreq_frequency_table *powernow_table)
 846 {
 847         int i;
 848
 849         for (i = 0; i < data->acpi_data.state_count; i++) {
 850                 u32 fid;
 851                 u32 vid;
 852                 u32 freq, index;
 853                 u64 status, control;
 854
 855                 if (data->exttype) {
 856                         status =  data->acpi_data.states[i].status;
 857                         fid = status & EXT_FID_MASK;
 858                         vid = (status >> VID_SHIFT) & EXT_VID_MASK;
 859                 } else {
 860                         control =  data->acpi_data.states[i].control;
 861                         fid = control & FID_MASK;
 862                         vid = (control >> VID_SHIFT) & VID_MASK;
 863                 }
 864
 865                 pr_debug("   %d : fid 0x%x, vid 0x%x\n", i, fid, vid);
 866
 867                 index = fid | (vid<<8);
 868                 powernow_table[i].index = index;
 869
 870                 freq = find_khz_freq_from_fid(fid);
 871                 powernow_table[i].frequency = freq;
 872
 873                 /* verify frequency is OK */
 874                 if ((freq > (MAX_FREQ * 1000)) || (freq < (MIN_FREQ * 1000))) {
 875                         pr_debug("invalid freq %u kHz, ignoring\n", freq);
 876                         invalidate_entry(powernow_table, i);
 877                         continue;
 878                 }
 879
 880                 /* verify voltage is OK -
 881                  * BIOSs are using "off" to indicate invalid */
 882                 if (vid == VID_OFF) {
 883                         pr_debug("invalid vid %u, ignoring\n", vid);
 884                         invalidate_entry(powernow_table, i);
 885                         continue;
 886                 }
 887
 888                 if (freq != (data->acpi_data.states[i].core_frequency * 1000)) {
 889                         printk(KERN_INFO PFX "invalid freq entries "
 890                                 "%u kHz vs. %u kHz\n", freq,
 891                                 (unsigned int)
 892                                 (data->acpi_data.states[i].core_frequency
 893                                  * 1000));
 894                         invalidate_entry(powernow_table, i);
 895                         continue;
 896                 }
 897         }
 898         return 0;
 899 }
 900
 901 static void powernow_k8_cpu_exit_acpi(struct powernow_k8_data *data)
 902 {
 903         if (data->acpi_data.state_count)
 904                 acpi_processor_unregister_performance(&data->acpi_data,
 905                                 data->cpu);
 906         free_cpumask_var(data->acpi_data.shared_cpu_map);
 907 }
 908
 909 static int get_transition_latency(struct powernow_k8_data *data)
 910 {
 911         int max_latency = 0;
 912         int i;
 913         for (i = 0; i < data->acpi_data.state_count; i++) {
 914                 int cur_latency = data->acpi_data.states[i].transition_latency
 915                         + data->acpi_data.states[i].bus_master_latency;
 916                 if (cur_latency > max_latency)
 917                         max_latency = cur_latency;
 918         }
 919         if (max_latency == 0) {
 920                 pr_err(FW_WARN PFX "Invalid zero transition latency\n");
 921                 max_latency = 1;
 922         }
 923         /* value in usecs, needs to be in nanoseconds */
 924         return 1000 * max_latency;
 925 }
 926
 927 /* Take a frequency, and issue the fid/vid transition command */
 928 static int transition_frequency_fidvid(struct powernow_k8_data *data,
 929                 unsigned int index)
 930 {
 931         u32 fid = 0;
 932         u32 vid = 0;
 933         int res, i;
 934         struct cpufreq_freqs freqs;
 935
 936         pr_debug("cpu %d transition to index %u\n", smp_processor_id(), index);
 937
 938         /* fid/vid correctness check for k8 */
 939         /* fid are the lower 8 bits of the index we stored into
 940          * the cpufreq frequency table in find_psb_table, vid
 941          * are the upper 8 bits.
 942          */
 943         fid = data->powernow_table[index].index & 0xFF;
 944         vid = (data->powernow_table[index].index & 0xFF00) >> 8;
 945
 946         pr_debug("table matched fid 0x%x, giving vid 0x%x\n", fid, vid);
 947
 948         if (query_current_values_with_pending_wait(data))
 949                 return 1;
 950
 951         if ((data->currvid == vid) && (data->currfid == fid)) {
 952                 pr_debug("target matches current values (fid 0x%x, vid 0x%x)\n",
 953                         fid, vid);
 954                 return 0;
 955         }
 956
 957         pr_debug("cpu %d, changing to fid 0x%x, vid 0x%x\n",
 958                 smp_processor_id(), fid, vid);
 959         freqs.old = find_khz_freq_from_fid(data->currfid);
 960         freqs.new = find_khz_freq_from_fid(fid);
 961
 962         for_each_cpu(i, data->available_cores) {
 963                 freqs.cpu = i;
 964                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 965         }
 966
 967         res = transition_fid_vid(data, fid, vid);
 968         if (res)
 969                 return res;
 970
 971         freqs.new = find_khz_freq_from_fid(data->currfid);
 972
 973         for_each_cpu(i, data->available_cores) {
 974                 freqs.cpu = i;
 975                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 976         }
 977         return res;
 978 }
 979
 980 struct powernowk8_target_arg {
 981         struct cpufreq_policy           *pol;
 982         unsigned                        targfreq;
 983         unsigned                        relation;
 984 };
 985
 986 static long powernowk8_target_fn(void *arg)
 987 {
 988         struct powernowk8_target_arg *pta = arg;
 989         struct cpufreq_policy *pol = pta->pol;
 990         unsigned targfreq = pta->targfreq;
 991         unsigned relation = pta->relation;
 992         struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
 993         u32 checkfid;
 994         u32 checkvid;
 995         unsigned int newstate;
 996         int ret;
 997
 998         if (!data)
 999                 return -EINVAL;
1000
1001         checkfid = data->currfid;
1002         checkvid = data->currvid;
1003
1004         if (pending_bit_stuck()) {
1005                 printk(KERN_ERR PFX "failing targ, change pending bit set\n");
1006                 return -EIO;
1007         }
1008
1009         pr_debug("targ: cpu %d, %d kHz, min %d, max %d, relation %d\n",
1010                 pol->cpu, targfreq, pol->min, pol->max, relation);
1011
1012         if (query_current_values_with_pending_wait(data))
1013                 return -EIO;
1014
1015         pr_debug("targ: curr fid 0x%x, vid 0x%x\n",
1016                  data->currfid, data->currvid);
1017
1018         if ((checkvid != data->currvid) ||
1019             (checkfid != data->currfid)) {
1020                 pr_info(PFX
1021                        "error - out of sync, fix 0x%x 0x%x, vid 0x%x 0x%x\n",
1022                        checkfid, data->currfid,
1023                        checkvid, data->currvid);
1024         }
1025
1026         if (cpufreq_frequency_table_target(pol, data->powernow_table,
1027                                 targfreq, relation, &newstate))
1028                 return -EIO;
1029
1030         mutex_lock(&fidvid_mutex);
1031
1032         powernow_k8_acpi_pst_values(data, newstate);
1033
1034         ret = transition_frequency_fidvid(data, newstate);
1035
1036         if (ret) {
1037                 printk(KERN_ERR PFX "transition frequency failed\n");
1038                 mutex_unlock(&fidvid_mutex);
1039                 return 1;
1040         }
1041         mutex_unlock(&fidvid_mutex);
1042
1043         pol->cur = find_khz_freq_from_fid(data->currfid);
1044
1045         return 0;
1046 }
1047
1048 /* Driver entry point to switch to the target frequency */
1049 static int powernowk8_target(struct cpufreq_policy *pol,
1050                 unsigned targfreq, unsigned relation)
1051 {
1052         struct powernowk8_target_arg pta = { .pol = pol, .targfreq = targfreq,
1053                                              .relation = relation };
1054
1055         return work_on_cpu(pol->cpu, powernowk8_target_fn, &pta);
1056 }
1057
1058 /* Driver entry point to verify the policy and range of frequencies */
1059 static int powernowk8_verify(struct cpufreq_policy *pol)
1060 {
1061         struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
1062
1063         if (!data)
1064                 return -EINVAL;
1065
1066         return cpufreq_frequency_table_verify(pol, data->powernow_table);
1067 }
1068
1069 struct init_on_cpu {
1070         struct powernow_k8_data *data;
1071         int rc;
1072 };
1073
1074 static void __cpuinit powernowk8_cpu_init_on_cpu(void *_init_on_cpu)
1075 {
1076         struct init_on_cpu *init_on_cpu = _init_on_cpu;
1077
1078         if (pending_bit_stuck()) {
1079                 printk(KERN_ERR PFX "failing init, change pending bit set\n");
1080                 init_on_cpu->rc = -ENODEV;
1081                 return;
1082         }
1083
1084         if (query_current_values_with_pending_wait(init_on_cpu->data)) {
1085                 init_on_cpu->rc = -ENODEV;
1086                 return;
1087         }
1088
1089         fidvid_msr_init();
1090
1091         init_on_cpu->rc = 0;
1092 }
1093
1094 static const char missing_pss_msg[] =
1095         KERN_ERR
1096         FW_BUG PFX "No compatible ACPI _PSS objects found.\n"
1097         FW_BUG PFX "First, make sure Cool'N'Quiet is enabled in the BIOS.\n"
1098         FW_BUG PFX "If that doesn't help, try upgrading your BIOS.\n";
1099
1100 /* per CPU init entry point to the driver */
1101 static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
1102 {
1103         struct powernow_k8_data *data;
1104         struct init_on_cpu init_on_cpu;
1105         int rc;
1106
1107         if (!cpu_online(pol->cpu))
1108                 return -ENODEV;
1109
1110         smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1);
1111         if (rc)
1112                 return -ENODEV;
1113
1114         data = kzalloc(sizeof(struct powernow_k8_data), GFP_KERNEL);
1115         if (!data) {
1116                 printk(KERN_ERR PFX "unable to alloc powernow_k8_data");
1117                 return -ENOMEM;
1118         }
1119
1120         data->cpu = pol->cpu;
1121
1122         if (powernow_k8_cpu_init_acpi(data)) {
1123                 /*
1124                  * Use the PSB BIOS structure. This is only available on
1125                  * an UP version, and is deprecated by AMD.
1126                  */
1127                 if (num_online_cpus() != 1) {
1128                         printk_once(missing_pss_msg);
1129                         goto err_out;
1130                 }
1131                 if (pol->cpu != 0) {
1132                         printk(KERN_ERR FW_BUG PFX "No ACPI _PSS objects for "
1133                                "CPU other than CPU0. Complain to your BIOS "
1134                                "vendor.\n");
1135                         goto err_out;
1136                 }
1137                 rc = find_psb_table(data);
1138                 if (rc)
1139                         goto err_out;
1140
1141                 /* Take a crude guess here.
1142                  * That guess was in microseconds, so multiply with 1000 */
1143                 pol->cpuinfo.transition_latency = (
1144                          ((data->rvo + 8) * data->vstable * VST_UNITS_20US) +
1145                          ((1 << data->irt) * 30)) * 1000;
1146         } else /* ACPI _PSS objects available */
1147                 pol->cpuinfo.transition_latency = get_transition_latency(data);
1148
1149         /* only run on specific CPU from here on */
1150         init_on_cpu.data = data;
1151         smp_call_function_single(data->cpu, powernowk8_cpu_init_on_cpu,
1152                                  &init_on_cpu, 1);
1153         rc = init_on_cpu.rc;
1154         if (rc != 0)
1155                 goto err_out_exit_acpi;
1156
1157         cpumask_copy(pol->cpus, cpu_core_mask(pol->cpu));
1158         data->available_cores = pol->cpus;
1159
1160         pol->cur = find_khz_freq_from_fid(data->currfid);
1161         pr_debug("policy current frequency %d kHz\n", pol->cur);
1162
1163         /* min/max the cpu is capable of */
1164         if (cpufreq_frequency_table_cpuinfo(pol, data->powernow_table)) {
1165                 printk(KERN_ERR FW_BUG PFX "invalid powernow_table\n");
1166                 powernow_k8_cpu_exit_acpi(data);
1167                 kfree(data->powernow_table);
1168                 kfree(data);
1169                 return -EINVAL;
1170         }
1171
1172         cpufreq_frequency_table_get_attr(data->powernow_table, pol->cpu);
1173
1174         pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n",
1175                  data->currfid, data->currvid);
1176
1177         per_cpu(powernow_data, pol->cpu) = data;
1178
1179         return 0;
1180
1181 err_out_exit_acpi:
1182         powernow_k8_cpu_exit_acpi(data);
1183
1184 err_out:
1185         kfree(data);
1186         return -ENODEV;
1187 }
1188
1189 static int powernowk8_cpu_exit(struct cpufreq_policy *pol)
1190 {
1191         struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
1192
1193         if (!data)
1194                 return -EINVAL;
1195
1196         powernow_k8_cpu_exit_acpi(data);
1197
1198         cpufreq_frequency_table_put_attr(pol->cpu);
1199
1200         kfree(data->powernow_table);
1201         kfree(data);
1202         per_cpu(powernow_data, pol->cpu) = NULL;
1203
1204         return 0;
1205 }
1206
1207 static void query_values_on_cpu(void *_err)
1208 {
1209         int *err = _err;
1210         struct powernow_k8_data *data = __this_cpu_read(powernow_data);
1211
1212         *err = query_current_values_with_pending_wait(data);
1213 }
1214
1215 static unsigned int powernowk8_get(unsigned int cpu)
1216 {
1217         struct powernow_k8_data *data = per_cpu(powernow_data, cpu);
1218         unsigned int khz = 0;
1219         int err;
1220
1221         if (!data)
1222                 return 0;
1223
1224         smp_call_function_single(cpu, query_values_on_cpu, &err, true);
1225         if (err)
1226                 goto out;
1227
1228         khz = find_khz_freq_from_fid(data->currfid);
1229
1230
1231 out:
1232         return khz;
1233 }
1234
1235 static struct freq_attr *powernow_k8_attr[] = {
1236         &cpufreq_freq_attr_scaling_available_freqs,
1237         NULL,
1238 };
1239
1240 static struct cpufreq_driver cpufreq_amd64_driver = {
1241         .verify         = powernowk8_verify,
1242         .target         = powernowk8_target,
1243         .bios_limit     = acpi_processor_get_bios_limit,
1244         .init           = powernowk8_cpu_init,
1245         .exit           = powernowk8_cpu_exit,
1246         .get            = powernowk8_get,
1247         .name           = "powernow-k8",
1248         .owner          = THIS_MODULE,
1249         .attr           = powernow_k8_attr,
1250 };
1251
1252 static void __request_acpi_cpufreq(void)
1253 {
1254         const char *cur_drv, *drv = "acpi-cpufreq";
1255
1256         cur_drv = cpufreq_get_current_driver();
1257         if (!cur_drv)
1258                 goto request;
1259
1260         if (strncmp(cur_drv, drv, min_t(size_t, strlen(cur_drv), strlen(drv))))
1261                 pr_warn(PFX "WTF driver: %s\n", cur_drv);
1262
1263         return;
1264
1265  request:
1266         pr_warn(PFX "This CPU is not supported anymore, using acpi-cpufreq instead.\n");
1267         request_module(drv);
1268 }
1269
1270 /* driver entry point for init */
1271 static int __cpuinit powernowk8_init(void)
1272 {
1273         unsigned int i, supported_cpus = 0;
1274         int ret;
1275
1276         if (static_cpu_has(X86_FEATURE_HW_PSTATE)) {
1277                 __request_acpi_cpufreq();
1278                 return -ENODEV;
1279         }
1280
1281         if (!x86_match_cpu(powernow_k8_ids))
1282                 return -ENODEV;
1283
1284         get_online_cpus();
1285         for_each_online_cpu(i) {
1286                 smp_call_function_single(i, check_supported_cpu, &ret, 1);
1287                 if (!ret)
1288                         supported_cpus++;
1289         }
1290
1291         if (supported_cpus != num_online_cpus()) {
1292                 put_online_cpus();
1293                 return -ENODEV;
1294         }
1295         put_online_cpus();
1296
1297         ret = cpufreq_register_driver(&cpufreq_amd64_driver);
1298         if (ret)
1299                 return ret;
1300
1301         pr_info(PFX "Found %d %s (%d cpu cores) (" VERSION ")\n",
1302                 num_online_nodes(), boot_cpu_data.x86_model_id, supported_cpus);
1303
1304         return ret;
1305 }
1306
1307 /* driver entry point for term */
1308 static void __exit powernowk8_exit(void)
1309 {
1310         pr_debug("exit\n");
1311
1312         cpufreq_unregister_driver(&cpufreq_amd64_driver);
1313 }
1314
1315 MODULE_AUTHOR("Paul Devriendt <paul.devriendt@amd.com> and "
1316                 "Mark Langsdorf <mark.langsdorf@amd.com>");
1317 MODULE_DESCRIPTION("AMD Athlon 64 and Opteron processor frequency driver.");
1318 MODULE_LICENSE("GPL");
1319
1320 late_initcall(powernowk8_init);
1321 module_exit(powernowk8_exit);