linux/drivers/cpufreq/powernow-k8.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *   (c) 2003-2012 Advanced Micro Devices, Inc.
   4 *
   5 *  Maintainer:
   6 *  Andreas Herrmann <herrmann.der.user@googlemail.com>
   7 *
   8 *  Based on the powernow-k7.c module written by Dave Jones.
   9 *  (C) 2003 Dave Jones on behalf of SuSE Labs
  10 *  (C) 2004 Dominik Brodowski <linux@brodo.de>
  11 *  (C) 2004 Pavel Machek <pavel@ucw.cz>
  12 *  Based upon datasheets & sample CPUs kindly provided by AMD.
  13 *
  14 *  Valuable input gratefully received from Dave Jones, Pavel Machek,
  15 *  Dominik Brodowski, Jacob Shin, and others.
  16 *  Originally developed by Paul Devriendt.
  17 *
  18 *  Processor information obtained from Chapter 9 (Power and Thermal
  19 *  Management) of the "BIOS and Kernel Developer's Guide (BKDG) for
  20 *  the AMD Athlon 64 and AMD Opteron Processors" and section "2.x
  21 *  Power Management" in BKDGs for newer AMD CPU families.
  22 *
  23 *  Tables for specific CPUs can be inferred from AMD's processor
  24 *  power and thermal data sheets, (e.g. 30417.pdf, 30430.pdf, 43375.pdf)
  25 */
  26
  27#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  28
  29#include <linux/kernel.h>
  30#include <linux/smp.h>
  31#include <linux/module.h>
  32#include <linux/init.h>
  33#include <linux/cpufreq.h>
  34#include <linux/slab.h>
  35#include <linux/string.h>
  36#include <linux/cpumask.h>
  37#include <linux/io.h>
  38#include <linux/delay.h>
  39
  40#include <asm/msr.h>
  41#include <asm/cpu_device_id.h>
  42
  43#include <linux/acpi.h>
  44#include <linux/mutex.h>
  45#include <acpi/processor.h>
  46
  47#define VERSION "version 2.20.00"
  48#include "powernow-k8.h"
  49
  50/* serialize freq changes  */
  51static DEFINE_MUTEX(fidvid_mutex);
  52
  53static DEFINE_PER_CPU(struct powernow_k8_data *, powernow_data);
  54
  55static struct cpufreq_driver cpufreq_amd64_driver;
  56
  57/* Return a frequency in MHz, given an input fid */
  58static u32 find_freq_from_fid(u32 fid)
  59{
  60        return 800 + (fid * 100);
  61}
  62
  63/* Return a frequency in KHz, given an input fid */
  64static u32 find_khz_freq_from_fid(u32 fid)
  65{
  66        return 1000 * find_freq_from_fid(fid);
  67}
  68
  69/* Return the vco fid for an input fid
  70 *
  71 * Each "low" fid has corresponding "high" fid, and you can get to "low" fids
  72 * only from corresponding high fids. This returns "high" fid corresponding to
  73 * "low" one.
  74 */
  75static u32 convert_fid_to_vco_fid(u32 fid)
  76{
  77        if (fid < HI_FID_TABLE_BOTTOM)
  78                return 8 + (2 * fid);
  79        else
  80                return fid;
  81}
  82
  83/*
  84 * Return 1 if the pending bit is set. Unless we just instructed the processor
  85 * to transition to a new state, seeing this bit set is really bad news.
  86 */
  87static int pending_bit_stuck(void)
  88{
  89        u32 lo, hi __always_unused;
  90
  91        rdmsr(MSR_FIDVID_STATUS, lo, hi);
  92        return lo & MSR_S_LO_CHANGE_PENDING ? 1 : 0;
  93}
  94
  95/*
  96 * Update the global current fid / vid values from the status msr.
  97 * Returns 1 on error.
  98 */
  99static int query_current_values_with_pending_wait(struct powernow_k8_data *data)
 100{
 101        u32 lo, hi;
 102        u32 i = 0;
 103
 104        do {
 105                if (i++ > 10000) {
 106                        pr_debug("detected change pending stuck\n");
 107                        return 1;
 108                }
 109                rdmsr(MSR_FIDVID_STATUS, lo, hi);
 110        } while (lo & MSR_S_LO_CHANGE_PENDING);
 111
 112        data->currvid = hi & MSR_S_HI_CURRENT_VID;
 113        data->currfid = lo & MSR_S_LO_CURRENT_FID;
 114
 115        return 0;
 116}
 117
 118/* the isochronous relief time */
 119static void count_off_irt(struct powernow_k8_data *data)
 120{
 121        udelay((1 << data->irt) * 10);
 122}
 123
 124/* the voltage stabilization time */
 125static void count_off_vst(struct powernow_k8_data *data)
 126{
 127        udelay(data->vstable * VST_UNITS_20US);
 128}
 129
 130/* need to init the control msr to a safe value (for each cpu) */
 131static void fidvid_msr_init(void)
 132{
 133        u32 lo, hi;
 134        u8 fid, vid;
 135
 136        rdmsr(MSR_FIDVID_STATUS, lo, hi);
 137        vid = hi & MSR_S_HI_CURRENT_VID;
 138        fid = lo & MSR_S_LO_CURRENT_FID;
 139        lo = fid | (vid << MSR_C_LO_VID_SHIFT);
 140        hi = MSR_C_HI_STP_GNT_BENIGN;
 141        pr_debug("cpu%d, init lo 0x%x, hi 0x%x\n", smp_processor_id(), lo, hi);
 142        wrmsr(MSR_FIDVID_CTL, lo, hi);
 143}
 144
 145/* write the new fid value along with the other control fields to the msr */
 146static int write_new_fid(struct powernow_k8_data *data, u32 fid)
 147{
 148        u32 lo;
 149        u32 savevid = data->currvid;
 150        u32 i = 0;
 151
 152        if ((fid & INVALID_FID_MASK) || (data->currvid & INVALID_VID_MASK)) {
 153                pr_err("internal error - overflow on fid write\n");
 154                return 1;
 155        }
 156
 157        lo = fid;
 158        lo |= (data->currvid << MSR_C_LO_VID_SHIFT);
 159        lo |= MSR_C_LO_INIT_FID_VID;
 160
 161        pr_debug("writing fid 0x%x, lo 0x%x, hi 0x%x\n",
 162                fid, lo, data->plllock * PLL_LOCK_CONVERSION);
 163
 164        do {
 165                wrmsr(MSR_FIDVID_CTL, lo, data->plllock * PLL_LOCK_CONVERSION);
 166                if (i++ > 100) {
 167                        pr_err("Hardware error - pending bit very stuck - no further pstate changes possible\n");
 168                        return 1;
 169                }
 170        } while (query_current_values_with_pending_wait(data));
 171
 172        count_off_irt(data);
 173
 174        if (savevid != data->currvid) {
 175                pr_err("vid change on fid trans, old 0x%x, new 0x%x\n",
 176                       savevid, data->currvid);
 177                return 1;
 178        }
 179
 180        if (fid != data->currfid) {
 181                pr_err("fid trans failed, fid 0x%x, curr 0x%x\n", fid,
 182                        data->currfid);
 183                return 1;
 184        }
 185
 186        return 0;
 187}
 188
 189/* Write a new vid to the hardware */
 190static int write_new_vid(struct powernow_k8_data *data, u32 vid)
 191{
 192        u32 lo;
 193        u32 savefid = data->currfid;
 194        int i = 0;
 195
 196        if ((data->currfid & INVALID_FID_MASK) || (vid & INVALID_VID_MASK)) {
 197                pr_err("internal error - overflow on vid write\n");
 198                return 1;
 199        }
 200
 201        lo = data->currfid;
 202        lo |= (vid << MSR_C_LO_VID_SHIFT);
 203        lo |= MSR_C_LO_INIT_FID_VID;
 204
 205        pr_debug("writing vid 0x%x, lo 0x%x, hi 0x%x\n",
 206                vid, lo, STOP_GRANT_5NS);
 207
 208        do {
 209                wrmsr(MSR_FIDVID_CTL, lo, STOP_GRANT_5NS);
 210                if (i++ > 100) {
 211                        pr_err("internal error - pending bit very stuck - no further pstate changes possible\n");
 212                        return 1;
 213                }
 214        } while (query_current_values_with_pending_wait(data));
 215
 216        if (savefid != data->currfid) {
 217                pr_err("fid changed on vid trans, old 0x%x new 0x%x\n",
 218                        savefid, data->currfid);
 219                return 1;
 220        }
 221
 222        if (vid != data->currvid) {
 223                pr_err("vid trans failed, vid 0x%x, curr 0x%x\n",
 224                                vid, data->currvid);
 225                return 1;
 226        }
 227
 228        return 0;
 229}
 230
 231/*
 232 * Reduce the vid by the max of step or reqvid.
 233 * Decreasing vid codes represent increasing voltages:
 234 * vid of 0 is 1.550V, vid of 0x1e is 0.800V, vid of VID_OFF is off.
 235 */
 236static int decrease_vid_code_by_step(struct powernow_k8_data *data,
 237                u32 reqvid, u32 step)
 238{
 239        if ((data->currvid - reqvid) > step)
 240                reqvid = data->currvid - step;
 241
 242        if (write_new_vid(data, reqvid))
 243                return 1;
 244
 245        count_off_vst(data);
 246
 247        return 0;
 248}
 249
 250/* Change Opteron/Athlon64 fid and vid, by the 3 phases. */
 251static int transition_fid_vid(struct powernow_k8_data *data,
 252                u32 reqfid, u32 reqvid)
 253{
 254        if (core_voltage_pre_transition(data, reqvid, reqfid))
 255                return 1;
 256
 257        if (core_frequency_transition(data, reqfid))
 258                return 1;
 259
 260        if (core_voltage_post_transition(data, reqvid))
 261                return 1;
 262
 263        if (query_current_values_with_pending_wait(data))
 264                return 1;
 265
 266        if ((reqfid != data->currfid) || (reqvid != data->currvid)) {
 267                pr_err("failed (cpu%d): req 0x%x 0x%x, curr 0x%x 0x%x\n",
 268                                smp_processor_id(),
 269                                reqfid, reqvid, data->currfid, data->currvid);
 270                return 1;
 271        }
 272
 273        pr_debug("transitioned (cpu%d): new fid 0x%x, vid 0x%x\n",
 274                smp_processor_id(), data->currfid, data->currvid);
 275
 276        return 0;
 277}
 278
 279/* Phase 1 - core voltage transition ... setup voltage */
 280static int core_voltage_pre_transition(struct powernow_k8_data *data,
 281                u32 reqvid, u32 reqfid)
 282{
 283        u32 rvosteps = data->rvo;
 284        u32 savefid = data->currfid;
 285        u32 maxvid, lo __always_unused, rvomult = 1;
 286
 287        pr_debug("ph1 (cpu%d): start, currfid 0x%x, currvid 0x%x, reqvid 0x%x, rvo 0x%x\n",
 288                smp_processor_id(),
 289                data->currfid, data->currvid, reqvid, data->rvo);
 290
 291        if ((savefid < LO_FID_TABLE_TOP) && (reqfid < LO_FID_TABLE_TOP))
 292                rvomult = 2;
 293        rvosteps *= rvomult;
 294        rdmsr(MSR_FIDVID_STATUS, lo, maxvid);
 295        maxvid = 0x1f & (maxvid >> 16);
 296        pr_debug("ph1 maxvid=0x%x\n", maxvid);
 297        if (reqvid < maxvid) /* lower numbers are higher voltages */
 298                reqvid = maxvid;
 299
 300        while (data->currvid > reqvid) {
 301                pr_debug("ph1: curr 0x%x, req vid 0x%x\n",
 302                        data->currvid, reqvid);
 303                if (decrease_vid_code_by_step(data, reqvid, data->vidmvs))
 304                        return 1;
 305        }
 306
 307        while ((rvosteps > 0) &&
 308                        ((rvomult * data->rvo + data->currvid) > reqvid)) {
 309                if (data->currvid == maxvid) {
 310                        rvosteps = 0;
 311                } else {
 312                        pr_debug("ph1: changing vid for rvo, req 0x%x\n",
 313                                data->currvid - 1);
 314                        if (decrease_vid_code_by_step(data, data->currvid-1, 1))
 315                                return 1;
 316                        rvosteps--;
 317                }
 318        }
 319
 320        if (query_current_values_with_pending_wait(data))
 321                return 1;
 322
 323        if (savefid != data->currfid) {
 324                pr_err("ph1 err, currfid changed 0x%x\n", data->currfid);
 325                return 1;
 326        }
 327
 328        pr_debug("ph1 complete, currfid 0x%x, currvid 0x%x\n",
 329                data->currfid, data->currvid);
 330
 331        return 0;
 332}
 333
 334/* Phase 2 - core frequency transition */
 335static int core_frequency_transition(struct powernow_k8_data *data, u32 reqfid)
 336{
 337        u32 vcoreqfid, vcocurrfid, vcofiddiff;
 338        u32 fid_interval, savevid = data->currvid;
 339
 340        if (data->currfid == reqfid) {
 341                pr_err("ph2 null fid transition 0x%x\n", data->currfid);
 342                return 0;
 343        }
 344
 345        pr_debug("ph2 (cpu%d): starting, currfid 0x%x, currvid 0x%x, reqfid 0x%x\n",
 346                smp_processor_id(),
 347                data->currfid, data->currvid, reqfid);
 348
 349        vcoreqfid = convert_fid_to_vco_fid(reqfid);
 350        vcocurrfid = convert_fid_to_vco_fid(data->currfid);
 351        vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
 352            : vcoreqfid - vcocurrfid;
 353
 354        if ((reqfid <= LO_FID_TABLE_TOP) && (data->currfid <= LO_FID_TABLE_TOP))
 355                vcofiddiff = 0;
 356
 357        while (vcofiddiff > 2) {
 358                (data->currfid & 1) ? (fid_interval = 1) : (fid_interval = 2);
 359
 360                if (reqfid > data->currfid) {
 361                        if (data->currfid > LO_FID_TABLE_TOP) {
 362                                if (write_new_fid(data,
 363                                                data->currfid + fid_interval))
 364                                        return 1;
 365                        } else {
 366                                if (write_new_fid
 367                                    (data,
 368                                     2 + convert_fid_to_vco_fid(data->currfid)))
 369                                        return 1;
 370                        }
 371                } else {
 372                        if (write_new_fid(data, data->currfid - fid_interval))
 373                                return 1;
 374                }
 375
 376                vcocurrfid = convert_fid_to_vco_fid(data->currfid);
 377                vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
 378                    : vcoreqfid - vcocurrfid;
 379        }
 380
 381        if (write_new_fid(data, reqfid))
 382                return 1;
 383
 384        if (query_current_values_with_pending_wait(data))
 385                return 1;
 386
 387        if (data->currfid != reqfid) {
 388                pr_err("ph2: mismatch, failed fid transition, curr 0x%x, req 0x%x\n",
 389                        data->currfid, reqfid);
 390                return 1;
 391        }
 392
 393        if (savevid != data->currvid) {
 394                pr_err("ph2: vid changed, save 0x%x, curr 0x%x\n",
 395                        savevid, data->currvid);
 396                return 1;
 397        }
 398
 399        pr_debug("ph2 complete, currfid 0x%x, currvid 0x%x\n",
 400                data->currfid, data->currvid);
 401
 402        return 0;
 403}
 404
 405/* Phase 3 - core voltage transition flow ... jump to the final vid. */
 406static int core_voltage_post_transition(struct powernow_k8_data *data,
 407                u32 reqvid)
 408{
 409        u32 savefid = data->currfid;
 410        u32 savereqvid = reqvid;
 411
 412        pr_debug("ph3 (cpu%d): starting, currfid 0x%x, currvid 0x%x\n",
 413                smp_processor_id(),
 414                data->currfid, data->currvid);
 415
 416        if (reqvid != data->currvid) {
 417                if (write_new_vid(data, reqvid))
 418                        return 1;
 419
 420                if (savefid != data->currfid) {
 421                        pr_err("ph3: bad fid change, save 0x%x, curr 0x%x\n",
 422                                savefid, data->currfid);
 423                        return 1;
 424                }
 425
 426                if (data->currvid != reqvid) {
 427                        pr_err("ph3: failed vid transition\n, req 0x%x, curr 0x%x",
 428                                reqvid, data->currvid);
 429                        return 1;
 430                }
 431        }
 432
 433        if (query_current_values_with_pending_wait(data))
 434                return 1;
 435
 436        if (savereqvid != data->currvid) {
 437                pr_debug("ph3 failed, currvid 0x%x\n", data->currvid);
 438                return 1;
 439        }
 440
 441        if (savefid != data->currfid) {
 442                pr_debug("ph3 failed, currfid changed 0x%x\n",
 443                        data->currfid);
 444                return 1;
 445        }
 446
 447        pr_debug("ph3 complete, currfid 0x%x, currvid 0x%x\n",
 448                data->currfid, data->currvid);
 449
 450        return 0;
 451}
 452
 453static const struct x86_cpu_id powernow_k8_ids[] = {
 454        /* IO based frequency switching */
 455        X86_MATCH_VENDOR_FAM(AMD, 0xf, NULL),
 456        {}
 457};
 458MODULE_DEVICE_TABLE(x86cpu, powernow_k8_ids);
 459
 460static void check_supported_cpu(void *_rc)
 461{
 462        u32 eax, ebx, ecx, edx;
 463        int *rc = _rc;
 464
 465        *rc = -ENODEV;
 466
 467        eax = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
 468
 469        if ((eax & CPUID_XFAM) == CPUID_XFAM_K8) {
 470                if (((eax & CPUID_USE_XFAM_XMOD) != CPUID_USE_XFAM_XMOD) ||
 471                    ((eax & CPUID_XMOD) > CPUID_XMOD_REV_MASK)) {
 472                        pr_info("Processor cpuid %x not supported\n", eax);
 473                        return;
 474                }
 475
 476                eax = cpuid_eax(CPUID_GET_MAX_CAPABILITIES);
 477                if (eax < CPUID_FREQ_VOLT_CAPABILITIES) {
 478                        pr_info("No frequency change capabilities detected\n");
 479                        return;
 480                }
 481
 482                cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
 483                if ((edx & P_STATE_TRANSITION_CAPABLE)
 484                        != P_STATE_TRANSITION_CAPABLE) {
 485                        pr_info("Power state transitions not supported\n");
 486                        return;
 487                }
 488                *rc = 0;
 489        }
 490}
 491
 492static int check_pst_table(struct powernow_k8_data *data, struct pst_s *pst,
 493                u8 maxvid)
 494{
 495        unsigned int j;
 496        u8 lastfid = 0xff;
 497
 498        for (j = 0; j < data->numps; j++) {
 499                if (pst[j].vid > LEAST_VID) {
 500                        pr_err(FW_BUG "vid %d invalid : 0x%x\n", j,
 501                                pst[j].vid);
 502                        return -EINVAL;
 503                }
 504                if (pst[j].vid < data->rvo) {
 505                        /* vid + rvo >= 0 */
 506                        pr_err(FW_BUG "0 vid exceeded with pstate %d\n", j);
 507                        return -ENODEV;
 508                }
 509                if (pst[j].vid < maxvid + data->rvo) {
 510                        /* vid + rvo >= maxvid */
 511                        pr_err(FW_BUG "maxvid exceeded with pstate %d\n", j);
 512                        return -ENODEV;
 513                }
 514                if (pst[j].fid > MAX_FID) {
 515                        pr_err(FW_BUG "maxfid exceeded with pstate %d\n", j);
 516                        return -ENODEV;
 517                }
 518                if (j && (pst[j].fid < HI_FID_TABLE_BOTTOM)) {
 519                        /* Only first fid is allowed to be in "low" range */
 520                        pr_err(FW_BUG "two low fids - %d : 0x%x\n", j,
 521                                pst[j].fid);
 522                        return -EINVAL;
 523                }
 524                if (pst[j].fid < lastfid)
 525                        lastfid = pst[j].fid;
 526        }
 527        if (lastfid & 1) {
 528                pr_err(FW_BUG "lastfid invalid\n");
 529                return -EINVAL;
 530        }
 531        if (lastfid > LO_FID_TABLE_TOP)
 532                pr_info(FW_BUG "first fid not from lo freq table\n");
 533
 534        return 0;
 535}
 536
 537static void invalidate_entry(struct cpufreq_frequency_table *powernow_table,
 538                unsigned int entry)
 539{
 540        powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
 541}
 542
 543static void print_basics(struct powernow_k8_data *data)
 544{
 545        int j;
 546        for (j = 0; j < data->numps; j++) {
 547                if (data->powernow_table[j].frequency !=
 548                                CPUFREQ_ENTRY_INVALID) {
 549                        pr_info("fid 0x%x (%d MHz), vid 0x%x\n",
 550                                data->powernow_table[j].driver_data & 0xff,
 551                                data->powernow_table[j].frequency/1000,
 552                                data->powernow_table[j].driver_data >> 8);
 553                }
 554        }
 555        if (data->batps)
 556                pr_info("Only %d pstates on battery\n", data->batps);
 557}
 558
 559static int fill_powernow_table(struct powernow_k8_data *data,
 560                struct pst_s *pst, u8 maxvid)
 561{
 562        struct cpufreq_frequency_table *powernow_table;
 563        unsigned int j;
 564
 565        if (data->batps) {
 566                /* use ACPI support to get full speed on mains power */
 567                pr_warn("Only %d pstates usable (use ACPI driver for full range\n",
 568                        data->batps);
 569                data->numps = data->batps;
 570        }
 571
 572        for (j = 1; j < data->numps; j++) {
 573                if (pst[j-1].fid >= pst[j].fid) {
 574                        pr_err("PST out of sequence\n");
 575                        return -EINVAL;
 576                }
 577        }
 578
 579        if (data->numps < 2) {
 580                pr_err("no p states to transition\n");
 581                return -ENODEV;
 582        }
 583
 584        if (check_pst_table(data, pst, maxvid))
 585                return -EINVAL;
 586
 587        powernow_table = kzalloc((sizeof(*powernow_table)
 588                * (data->numps + 1)), GFP_KERNEL);
 589        if (!powernow_table)
 590                return -ENOMEM;
 591
 592        for (j = 0; j < data->numps; j++) {
 593                int freq;
 594                powernow_table[j].driver_data = pst[j].fid; /* lower 8 bits */
 595                powernow_table[j].driver_data |= (pst[j].vid << 8); /* upper 8 bits */
 596                freq = find_khz_freq_from_fid(pst[j].fid);
 597                powernow_table[j].frequency = freq;
 598        }
 599        powernow_table[data->numps].frequency = CPUFREQ_TABLE_END;
 600        powernow_table[data->numps].driver_data = 0;
 601
 602        if (query_current_values_with_pending_wait(data)) {
 603                kfree(powernow_table);
 604                return -EIO;
 605        }
 606
 607        pr_debug("cfid 0x%x, cvid 0x%x\n", data->currfid, data->currvid);
 608        data->powernow_table = powernow_table;
 609        if (cpumask_first(topology_core_cpumask(data->cpu)) == data->cpu)
 610                print_basics(data);
 611
 612        for (j = 0; j < data->numps; j++)
 613                if ((pst[j].fid == data->currfid) &&
 614                    (pst[j].vid == data->currvid))
 615                        return 0;
 616
 617        pr_debug("currfid/vid do not match PST, ignoring\n");
 618        return 0;
 619}
 620
 621/* Find and validate the PSB/PST table in BIOS. */
 622static int find_psb_table(struct powernow_k8_data *data)
 623{
 624        struct psb_s *psb;
 625        unsigned int i;
 626        u32 mvs;
 627        u8 maxvid;
 628        u32 cpst = 0;
 629        u32 thiscpuid;
 630
 631        for (i = 0xc0000; i < 0xffff0; i += 0x10) {
 632                /* Scan BIOS looking for the signature. */
 633                /* It can not be at ffff0 - it is too big. */
 634
 635                psb = phys_to_virt(i);
 636                if (memcmp(psb, PSB_ID_STRING, PSB_ID_STRING_LEN) != 0)
 637                        continue;
 638
 639                pr_debug("found PSB header at 0x%p\n", psb);
 640
 641                pr_debug("table vers: 0x%x\n", psb->tableversion);
 642                if (psb->tableversion != PSB_VERSION_1_4) {
 643                        pr_err(FW_BUG "PSB table is not v1.4\n");
 644                        return -ENODEV;
 645                }
 646
 647                pr_debug("flags: 0x%x\n", psb->flags1);
 648                if (psb->flags1) {
 649                        pr_err(FW_BUG "unknown flags\n");
 650                        return -ENODEV;
 651                }
 652
 653                data->vstable = psb->vstable;
 654                pr_debug("voltage stabilization time: %d(*20us)\n",
 655                                data->vstable);
 656
 657                pr_debug("flags2: 0x%x\n", psb->flags2);
 658                data->rvo = psb->flags2 & 3;
 659                data->irt = ((psb->flags2) >> 2) & 3;
 660                mvs = ((psb->flags2) >> 4) & 3;
 661                data->vidmvs = 1 << mvs;
 662                data->batps = ((psb->flags2) >> 6) & 3;
 663
 664                pr_debug("ramp voltage offset: %d\n", data->rvo);
 665                pr_debug("isochronous relief time: %d\n", data->irt);
 666                pr_debug("maximum voltage step: %d - 0x%x\n", mvs, data->vidmvs);
 667
 668                pr_debug("numpst: 0x%x\n", psb->num_tables);
 669                cpst = psb->num_tables;
 670                if ((psb->cpuid == 0x00000fc0) ||
 671                    (psb->cpuid == 0x00000fe0)) {
 672                        thiscpuid = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
 673                        if ((thiscpuid == 0x00000fc0) ||
 674                            (thiscpuid == 0x00000fe0))
 675                                cpst = 1;
 676                }
 677                if (cpst != 1) {
 678                        pr_err(FW_BUG "numpst must be 1\n");
 679                        return -ENODEV;
 680                }
 681
 682                data->plllock = psb->plllocktime;
 683                pr_debug("plllocktime: 0x%x (units 1us)\n", psb->plllocktime);
 684                pr_debug("maxfid: 0x%x\n", psb->maxfid);
 685                pr_debug("maxvid: 0x%x\n", psb->maxvid);
 686                maxvid = psb->maxvid;
 687
 688                data->numps = psb->numps;
 689                pr_debug("numpstates: 0x%x\n", data->numps);
 690                return fill_powernow_table(data,
 691                                (struct pst_s *)(psb+1), maxvid);
 692        }
 693        /*
 694         * If you see this message, complain to BIOS manufacturer. If
 695         * he tells you "we do not support Linux" or some similar
 696         * nonsense, remember that Windows 2000 uses the same legacy
 697         * mechanism that the old Linux PSB driver uses. Tell them it
 698         * is broken with Windows 2000.
 699         *
 700         * The reference to the AMD documentation is chapter 9 in the
 701         * BIOS and Kernel Developer's Guide, which is available on
 702         * www.amd.com
 703         */
 704        pr_err(FW_BUG "No PSB or ACPI _PSS objects\n");
 705        pr_err("Make sure that your BIOS is up to date and Cool'N'Quiet support is enabled in BIOS setup\n");
 706        return -ENODEV;
 707}
 708
 709static void powernow_k8_acpi_pst_values(struct powernow_k8_data *data,
 710                unsigned int index)
 711{
 712        u64 control;
 713
 714        if (!data->acpi_data.state_count)
 715                return;
 716
 717        control = data->acpi_data.states[index].control;
 718        data->irt = (control >> IRT_SHIFT) & IRT_MASK;
 719        data->rvo = (control >> RVO_SHIFT) & RVO_MASK;
 720        data->exttype = (control >> EXT_TYPE_SHIFT) & EXT_TYPE_MASK;
 721        data->plllock = (control >> PLL_L_SHIFT) & PLL_L_MASK;
 722        data->vidmvs = 1 << ((control >> MVS_SHIFT) & MVS_MASK);
 723        data->vstable = (control >> VST_SHIFT) & VST_MASK;
 724}
 725
 726static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data)
 727{
 728        struct cpufreq_frequency_table *powernow_table;
 729        int ret_val = -ENODEV;
 730        u64 control, status;
 731
 732        if (acpi_processor_register_performance(&data->acpi_data, data->cpu)) {
 733                pr_debug("register performance failed: bad ACPI data\n");
 734                return -EIO;
 735        }
 736
 737        /* verify the data contained in the ACPI structures */
 738        if (data->acpi_data.state_count <= 1) {
 739                pr_debug("No ACPI P-States\n");
 740                goto err_out;
 741        }
 742
 743        control = data->acpi_data.control_register.space_id;
 744        status = data->acpi_data.status_register.space_id;
 745
 746        if ((control != ACPI_ADR_SPACE_FIXED_HARDWARE) ||
 747            (status != ACPI_ADR_SPACE_FIXED_HARDWARE)) {
 748                pr_debug("Invalid control/status registers (%llx - %llx)\n",
 749                        control, status);
 750                goto err_out;
 751        }
 752
 753        /* fill in data->powernow_table */
 754        powernow_table = kzalloc((sizeof(*powernow_table)
 755                * (data->acpi_data.state_count + 1)), GFP_KERNEL);
 756        if (!powernow_table)
 757                goto err_out;
 758
 759        /* fill in data */
 760        data->numps = data->acpi_data.state_count;
 761        powernow_k8_acpi_pst_values(data, 0);
 762
 763        ret_val = fill_powernow_table_fidvid(data, powernow_table);
 764        if (ret_val)
 765                goto err_out_mem;
 766
 767        powernow_table[data->acpi_data.state_count].frequency =
 768                CPUFREQ_TABLE_END;
 769        data->powernow_table = powernow_table;
 770
 771        if (cpumask_first(topology_core_cpumask(data->cpu)) == data->cpu)
 772                print_basics(data);
 773
 774        /* notify BIOS that we exist */
 775        acpi_processor_notify_smm(THIS_MODULE);
 776
 777        if (!zalloc_cpumask_var(&data->acpi_data.shared_cpu_map, GFP_KERNEL)) {
 778                pr_err("unable to alloc powernow_k8_data cpumask\n");
 779                ret_val = -ENOMEM;
 780                goto err_out_mem;
 781        }
 782
 783        return 0;
 784
 785err_out_mem:
 786        kfree(powernow_table);
 787
 788err_out:
 789        acpi_processor_unregister_performance(data->cpu);
 790
 791        /* data->acpi_data.state_count informs us at ->exit()
 792         * whether ACPI was used */
 793        data->acpi_data.state_count = 0;
 794
 795        return ret_val;
 796}
 797
 798static int fill_powernow_table_fidvid(struct powernow_k8_data *data,
 799                struct cpufreq_frequency_table *powernow_table)
 800{
 801        int i;
 802
 803        for (i = 0; i < data->acpi_data.state_count; i++) {
 804                u32 fid;
 805                u32 vid;
 806                u32 freq, index;
 807                u64 status, control;
 808
 809                if (data->exttype) {
 810                        status =  data->acpi_data.states[i].status;
 811                        fid = status & EXT_FID_MASK;
 812                        vid = (status >> VID_SHIFT) & EXT_VID_MASK;
 813                } else {
 814                        control =  data->acpi_data.states[i].control;
 815                        fid = control & FID_MASK;
 816                        vid = (control >> VID_SHIFT) & VID_MASK;
 817                }
 818
 819                pr_debug("   %d : fid 0x%x, vid 0x%x\n", i, fid, vid);
 820
 821                index = fid | (vid<<8);
 822                powernow_table[i].driver_data = index;
 823
 824                freq = find_khz_freq_from_fid(fid);
 825                powernow_table[i].frequency = freq;
 826
 827                /* verify frequency is OK */
 828                if ((freq > (MAX_FREQ * 1000)) || (freq < (MIN_FREQ * 1000))) {
 829                        pr_debug("invalid freq %u kHz, ignoring\n", freq);
 830                        invalidate_entry(powernow_table, i);
 831                        continue;
 832                }
 833
 834                /* verify voltage is OK -
 835                 * BIOSs are using "off" to indicate invalid */
 836                if (vid == VID_OFF) {
 837                        pr_debug("invalid vid %u, ignoring\n", vid);
 838                        invalidate_entry(powernow_table, i);
 839                        continue;
 840                }
 841
 842                if (freq != (data->acpi_data.states[i].core_frequency * 1000)) {
 843                        pr_info("invalid freq entries %u kHz vs. %u kHz\n",
 844                                freq, (unsigned int)
 845                                (data->acpi_data.states[i].core_frequency
 846                                 * 1000));
 847                        invalidate_entry(powernow_table, i);
 848                        continue;
 849                }
 850        }
 851        return 0;
 852}
 853
 854static void powernow_k8_cpu_exit_acpi(struct powernow_k8_data *data)
 855{
 856        if (data->acpi_data.state_count)
 857                acpi_processor_unregister_performance(data->cpu);
 858        free_cpumask_var(data->acpi_data.shared_cpu_map);
 859}
 860
 861static int get_transition_latency(struct powernow_k8_data *data)
 862{
 863        int max_latency = 0;
 864        int i;
 865        for (i = 0; i < data->acpi_data.state_count; i++) {
 866                int cur_latency = data->acpi_data.states[i].transition_latency
 867                        + data->acpi_data.states[i].bus_master_latency;
 868                if (cur_latency > max_latency)
 869                        max_latency = cur_latency;
 870        }
 871        if (max_latency == 0) {
 872                pr_err(FW_WARN "Invalid zero transition latency\n");
 873                max_latency = 1;
 874        }
 875        /* value in usecs, needs to be in nanoseconds */
 876        return 1000 * max_latency;
 877}
 878
 879/* Take a frequency, and issue the fid/vid transition command */
 880static int transition_frequency_fidvid(struct powernow_k8_data *data,
 881                unsigned int index,
 882                struct cpufreq_policy *policy)
 883{
 884        u32 fid = 0;
 885        u32 vid = 0;
 886        int res;
 887        struct cpufreq_freqs freqs;
 888
 889        pr_debug("cpu %d transition to index %u\n", smp_processor_id(), index);
 890
 891        /* fid/vid correctness check for k8 */
 892        /* fid are the lower 8 bits of the index we stored into
 893         * the cpufreq frequency table in find_psb_table, vid
 894         * are the upper 8 bits.
 895         */
 896        fid = data->powernow_table[index].driver_data & 0xFF;
 897        vid = (data->powernow_table[index].driver_data & 0xFF00) >> 8;
 898
 899        pr_debug("table matched fid 0x%x, giving vid 0x%x\n", fid, vid);
 900
 901        if (query_current_values_with_pending_wait(data))
 902                return 1;
 903
 904        if ((data->currvid == vid) && (data->currfid == fid)) {
 905                pr_debug("target matches current values (fid 0x%x, vid 0x%x)\n",
 906                        fid, vid);
 907                return 0;
 908        }
 909
 910        pr_debug("cpu %d, changing to fid 0x%x, vid 0x%x\n",
 911                smp_processor_id(), fid, vid);
 912        freqs.old = find_khz_freq_from_fid(data->currfid);
 913        freqs.new = find_khz_freq_from_fid(fid);
 914
 915        cpufreq_freq_transition_begin(policy, &freqs);
 916        res = transition_fid_vid(data, fid, vid);
 917        cpufreq_freq_transition_end(policy, &freqs, res);
 918
 919        return res;
 920}
 921
 922struct powernowk8_target_arg {
 923        struct cpufreq_policy           *pol;
 924        unsigned                        newstate;
 925};
 926
 927static long powernowk8_target_fn(void *arg)
 928{
 929        struct powernowk8_target_arg *pta = arg;
 930        struct cpufreq_policy *pol = pta->pol;
 931        unsigned newstate = pta->newstate;
 932        struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
 933        u32 checkfid;
 934        u32 checkvid;
 935        int ret;
 936
 937        if (!data)
 938                return -EINVAL;
 939
 940        checkfid = data->currfid;
 941        checkvid = data->currvid;
 942
 943        if (pending_bit_stuck()) {
 944                pr_err("failing targ, change pending bit set\n");
 945                return -EIO;
 946        }
 947
 948        pr_debug("targ: cpu %d, %d kHz, min %d, max %d\n",
 949                pol->cpu, data->powernow_table[newstate].frequency, pol->min,
 950                pol->max);
 951
 952        if (query_current_values_with_pending_wait(data))
 953                return -EIO;
 954
 955        pr_debug("targ: curr fid 0x%x, vid 0x%x\n",
 956                data->currfid, data->currvid);
 957
 958        if ((checkvid != data->currvid) ||
 959            (checkfid != data->currfid)) {
 960                pr_info("error - out of sync, fix 0x%x 0x%x, vid 0x%x 0x%x\n",
 961                       checkfid, data->currfid,
 962                       checkvid, data->currvid);
 963        }
 964
 965        mutex_lock(&fidvid_mutex);
 966
 967        powernow_k8_acpi_pst_values(data, newstate);
 968
 969        ret = transition_frequency_fidvid(data, newstate, pol);
 970
 971        if (ret) {
 972                pr_err("transition frequency failed\n");
 973                mutex_unlock(&fidvid_mutex);
 974                return 1;
 975        }
 976        mutex_unlock(&fidvid_mutex);
 977
 978        pol->cur = find_khz_freq_from_fid(data->currfid);
 979
 980        return 0;
 981}
 982
 983/* Driver entry point to switch to the target frequency */
 984static int powernowk8_target(struct cpufreq_policy *pol, unsigned index)
 985{
 986        struct powernowk8_target_arg pta = { .pol = pol, .newstate = index };
 987
 988        return work_on_cpu(pol->cpu, powernowk8_target_fn, &pta);
 989}
 990
 991struct init_on_cpu {
 992        struct powernow_k8_data *data;
 993        int rc;
 994};
 995
 996static void powernowk8_cpu_init_on_cpu(void *_init_on_cpu)
 997{
 998        struct init_on_cpu *init_on_cpu = _init_on_cpu;
 999
1000        if (pending_bit_stuck()) {
1001                pr_err("failing init, change pending bit set\n");
1002                init_on_cpu->rc = -ENODEV;
1003                return;
1004        }
1005
1006        if (query_current_values_with_pending_wait(init_on_cpu->data)) {
1007                init_on_cpu->rc = -ENODEV;
1008                return;
1009        }
1010
1011        fidvid_msr_init();
1012
1013        init_on_cpu->rc = 0;
1014}
1015
1016#define MISSING_PSS_MSG \
1017        FW_BUG "No compatible ACPI _PSS objects found.\n" \
1018        FW_BUG "First, make sure Cool'N'Quiet is enabled in the BIOS.\n" \
1019        FW_BUG "If that doesn't help, try upgrading your BIOS.\n"
1020
1021/* per CPU init entry point to the driver */
1022static int powernowk8_cpu_init(struct cpufreq_policy *pol)
1023{
1024        struct powernow_k8_data *data;
1025        struct init_on_cpu init_on_cpu;
1026        int rc, cpu;
1027
1028        smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1);
1029        if (rc)
1030                return -ENODEV;
1031
1032        data = kzalloc(sizeof(*data), GFP_KERNEL);
1033        if (!data)
1034                return -ENOMEM;
1035
1036        data->cpu = pol->cpu;
1037
1038        if (powernow_k8_cpu_init_acpi(data)) {
1039                /*
1040                 * Use the PSB BIOS structure. This is only available on
1041                 * an UP version, and is deprecated by AMD.
1042                 */
1043                if (num_online_cpus() != 1) {
1044                        pr_err_once(MISSING_PSS_MSG);
1045                        goto err_out;
1046                }
1047                if (pol->cpu != 0) {
1048                        pr_err(FW_BUG "No ACPI _PSS objects for CPU other than CPU0. Complain to your BIOS vendor.\n");
1049                        goto err_out;
1050                }
1051                rc = find_psb_table(data);
1052                if (rc)
1053                        goto err_out;
1054
1055                /* Take a crude guess here.
1056                 * That guess was in microseconds, so multiply with 1000 */
1057                pol->cpuinfo.transition_latency = (
1058                         ((data->rvo + 8) * data->vstable * VST_UNITS_20US) +
1059                         ((1 << data->irt) * 30)) * 1000;
1060        } else /* ACPI _PSS objects available */
1061                pol->cpuinfo.transition_latency = get_transition_latency(data);
1062
1063        /* only run on specific CPU from here on */
1064        init_on_cpu.data = data;
1065        smp_call_function_single(data->cpu, powernowk8_cpu_init_on_cpu,
1066                                 &init_on_cpu, 1);
1067        rc = init_on_cpu.rc;
1068        if (rc != 0)
1069                goto err_out_exit_acpi;
1070
1071        cpumask_copy(pol->cpus, topology_core_cpumask(pol->cpu));
1072        data->available_cores = pol->cpus;
1073        pol->freq_table = data->powernow_table;
1074
1075        pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n",
1076                data->currfid, data->currvid);
1077
1078        /* Point all the CPUs in this policy to the same data */
1079        for_each_cpu(cpu, pol->cpus)
1080                per_cpu(powernow_data, cpu) = data;
1081
1082        return 0;
1083
1084err_out_exit_acpi:
1085        powernow_k8_cpu_exit_acpi(data);
1086
1087err_out:
1088        kfree(data);
1089        return -ENODEV;
1090}
1091
1092static int powernowk8_cpu_exit(struct cpufreq_policy *pol)
1093{
1094        struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
1095        int cpu;
1096
1097        if (!data)
1098                return -EINVAL;
1099
1100        powernow_k8_cpu_exit_acpi(data);
1101
1102        kfree(data->powernow_table);
1103        kfree(data);
1104        for_each_cpu(cpu, pol->cpus)
1105                per_cpu(powernow_data, cpu) = NULL;
1106
1107        return 0;
1108}
1109
1110static void query_values_on_cpu(void *_err)
1111{
1112        int *err = _err;
1113        struct powernow_k8_data *data = __this_cpu_read(powernow_data);
1114
1115        *err = query_current_values_with_pending_wait(data);
1116}
1117
1118static unsigned int powernowk8_get(unsigned int cpu)
1119{
1120        struct powernow_k8_data *data = per_cpu(powernow_data, cpu);
1121        unsigned int khz = 0;
1122        int err;
1123
1124        if (!data)
1125                return 0;
1126
1127        smp_call_function_single(cpu, query_values_on_cpu, &err, true);
1128        if (err)
1129                goto out;
1130
1131        khz = find_khz_freq_from_fid(data->currfid);
1132
1133
1134out:
1135        return khz;
1136}
1137
1138static struct cpufreq_driver cpufreq_amd64_driver = {
1139        .flags          = CPUFREQ_ASYNC_NOTIFICATION,
1140        .verify         = cpufreq_generic_frequency_table_verify,
1141        .target_index   = powernowk8_target,
1142        .bios_limit     = acpi_processor_get_bios_limit,
1143        .init           = powernowk8_cpu_init,
1144        .exit           = powernowk8_cpu_exit,
1145        .get            = powernowk8_get,
1146        .name           = "powernow-k8",
1147        .attr           = cpufreq_generic_attr,
1148};
1149
1150static void __request_acpi_cpufreq(void)
1151{
1152        const char drv[] = "acpi-cpufreq";
1153        const char *cur_drv;
1154
1155        cur_drv = cpufreq_get_current_driver();
1156        if (!cur_drv)
1157                goto request;
1158
1159        if (strncmp(cur_drv, drv, min_t(size_t, strlen(cur_drv), strlen(drv))))
1160                pr_warn("WTF driver: %s\n", cur_drv);
1161
1162        return;
1163
1164 request:
1165        pr_warn("This CPU is not supported anymore, using acpi-cpufreq instead.\n");
1166        request_module(drv);
1167}
1168
1169/* driver entry point for init */
1170static int powernowk8_init(void)
1171{
1172        unsigned int i, supported_cpus = 0;
1173        int ret;
1174
1175        if (boot_cpu_has(X86_FEATURE_HW_PSTATE)) {
1176                __request_acpi_cpufreq();
1177                return -ENODEV;
1178        }
1179
1180        if (!x86_match_cpu(powernow_k8_ids))
1181                return -ENODEV;
1182
1183        get_online_cpus();
1184        for_each_online_cpu(i) {
1185                smp_call_function_single(i, check_supported_cpu, &ret, 1);
1186                if (!ret)
1187                        supported_cpus++;
1188        }
1189
1190        if (supported_cpus != num_online_cpus()) {
1191                put_online_cpus();
1192                return -ENODEV;
1193        }
1194        put_online_cpus();
1195
1196        ret = cpufreq_register_driver(&cpufreq_amd64_driver);
1197        if (ret)
1198                return ret;
1199
1200        pr_info("Found %d %s (%d cpu cores) (" VERSION ")\n",
1201                num_online_nodes(), boot_cpu_data.x86_model_id, supported_cpus);
1202
1203        return ret;
1204}
1205
1206/* driver entry point for term */
1207static void __exit powernowk8_exit(void)
1208{
1209        pr_debug("exit\n");
1210
1211        cpufreq_unregister_driver(&cpufreq_amd64_driver);
1212}
1213
1214MODULE_AUTHOR("Paul Devriendt <paul.devriendt@amd.com>");
1215MODULE_AUTHOR("Mark Langsdorf <mark.langsdorf@amd.com>");
1216MODULE_DESCRIPTION("AMD Athlon 64 and Opteron processor frequency driver.");
1217MODULE_LICENSE("GPL");
1218
1219late_initcall(powernowk8_init);
1220module_exit(powernowk8_exit);
1221