drivers/cpufreq/powernow-k8.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
find_freq_from_fid
find_khz_freq_from_fid
convert_fid_to_vco_fid
pending_bit_stuck
query_current_values_with_pending_wait
count_off_irt
count_off_vst
fidvid_msr_init
write_new_fid
write_new_vid
decrease_vid_code_by_step
transition_fid_vid
core_voltage_pre_transition
core_frequency_transition
core_voltage_post_transition
check_supported_cpu
check_pst_table
invalidate_entry
print_basics
fill_powernow_table
find_psb_table
powernow_k8_acpi_pst_values
powernow_k8_cpu_init_acpi
fill_powernow_table_fidvid
powernow_k8_cpu_exit_acpi
get_transition_latency
transition_frequency_fidvid
powernowk8_target_fn
powernowk8_target
powernowk8_cpu_init_on_cpu
powernowk8_cpu_init
powernowk8_cpu_exit
query_values_on_cpu
powernowk8_get
__request_acpi_cpufreq
powernowk8_init
powernowk8_exit
   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  */
  51 static DEFINE_MUTEX(fidvid_mutex);
  52 
  53 static DEFINE_PER_CPU(struct powernow_k8_data *, powernow_data);
  54 
  55 static struct cpufreq_driver cpufreq_amd64_driver;
  56 
  57 /* Return a frequency in MHz, given an input fid */
  58 static 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 */
  64 static 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  */
  75 static 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  */
  87 static int pending_bit_stuck(void)
  88 {
  89         u32 lo, hi;
  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  */
  99 static 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 */
 119 static void count_off_irt(struct powernow_k8_data *data)
 120 {
 121         udelay((1 << data->irt) * 10);
 122 }
 123 
 124 /* the voltage stabilization time */
 125 static 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) */
 131 static 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 */
 146 static 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 */
 190 static 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  */
 236 static 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. */
 251 static 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 */
 280 static 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, 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 */
 335 static 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. */
 406 static 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 
 453 static const struct x86_cpu_id powernow_k8_ids[] = {
 454         /* IO based frequency switching */
 455         { X86_VENDOR_AMD, 0xf },
 456         {}
 457 };
 458 MODULE_DEVICE_TABLE(x86cpu, powernow_k8_ids);
 459 
 460 static 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 
 492 static 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 
 537 static void invalidate_entry(struct cpufreq_frequency_table *powernow_table,
 538                 unsigned int entry)
 539 {
 540         powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
 541 }
 542 
 543 static 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 
 559 static 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. */
 622 static 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 
 709 static 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 
 726 static 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 
 785 err_out_mem:
 786         kfree(powernow_table);
 787 
 788 err_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 
 798 static 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 
 854 static 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 
 861 static 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 */
 880 static int transition_frequency_fidvid(struct powernow_k8_data *data,
 881                 unsigned int index)
 882 {
 883         struct cpufreq_policy *policy;
 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         policy = cpufreq_cpu_get(smp_processor_id());
 916         cpufreq_cpu_put(policy);
 917 
 918         cpufreq_freq_transition_begin(policy, &freqs);
 919         res = transition_fid_vid(data, fid, vid);
 920         cpufreq_freq_transition_end(policy, &freqs, res);
 921 
 922         return res;
 923 }
 924 
 925 struct powernowk8_target_arg {
 926         struct cpufreq_policy           *pol;
 927         unsigned                        newstate;
 928 };
 929 
 930 static long powernowk8_target_fn(void *arg)
 931 {
 932         struct powernowk8_target_arg *pta = arg;
 933         struct cpufreq_policy *pol = pta->pol;
 934         unsigned newstate = pta->newstate;
 935         struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
 936         u32 checkfid;
 937         u32 checkvid;
 938         int ret;
 939 
 940         if (!data)
 941                 return -EINVAL;
 942 
 943         checkfid = data->currfid;
 944         checkvid = data->currvid;
 945 
 946         if (pending_bit_stuck()) {
 947                 pr_err("failing targ, change pending bit set\n");
 948                 return -EIO;
 949         }
 950 
 951         pr_debug("targ: cpu %d, %d kHz, min %d, max %d\n",
 952                 pol->cpu, data->powernow_table[newstate].frequency, pol->min,
 953                 pol->max);
 954 
 955         if (query_current_values_with_pending_wait(data))
 956                 return -EIO;
 957 
 958         pr_debug("targ: curr fid 0x%x, vid 0x%x\n",
 959                 data->currfid, data->currvid);
 960 
 961         if ((checkvid != data->currvid) ||
 962             (checkfid != data->currfid)) {
 963                 pr_info("error - out of sync, fix 0x%x 0x%x, vid 0x%x 0x%x\n",
 964                        checkfid, data->currfid,
 965                        checkvid, data->currvid);
 966         }
 967 
 968         mutex_lock(&fidvid_mutex);
 969 
 970         powernow_k8_acpi_pst_values(data, newstate);
 971 
 972         ret = transition_frequency_fidvid(data, newstate);
 973 
 974         if (ret) {
 975                 pr_err("transition frequency failed\n");
 976                 mutex_unlock(&fidvid_mutex);
 977                 return 1;
 978         }
 979         mutex_unlock(&fidvid_mutex);
 980 
 981         pol->cur = find_khz_freq_from_fid(data->currfid);
 982 
 983         return 0;
 984 }
 985 
 986 /* Driver entry point to switch to the target frequency */
 987 static int powernowk8_target(struct cpufreq_policy *pol, unsigned index)
 988 {
 989         struct powernowk8_target_arg pta = { .pol = pol, .newstate = index };
 990 
 991         return work_on_cpu(pol->cpu, powernowk8_target_fn, &pta);
 992 }
 993 
 994 struct init_on_cpu {
 995         struct powernow_k8_data *data;
 996         int rc;
 997 };
 998 
 999 static void powernowk8_cpu_init_on_cpu(void *_init_on_cpu)
1000 {
1001         struct init_on_cpu *init_on_cpu = _init_on_cpu;
1002 
1003         if (pending_bit_stuck()) {
1004                 pr_err("failing init, change pending bit set\n");
1005                 init_on_cpu->rc = -ENODEV;
1006                 return;
1007         }
1008 
1009         if (query_current_values_with_pending_wait(init_on_cpu->data)) {
1010                 init_on_cpu->rc = -ENODEV;
1011                 return;
1012         }
1013 
1014         fidvid_msr_init();
1015 
1016         init_on_cpu->rc = 0;
1017 }
1018 
1019 #define MISSING_PSS_MSG \
1020         FW_BUG "No compatible ACPI _PSS objects found.\n" \
1021         FW_BUG "First, make sure Cool'N'Quiet is enabled in the BIOS.\n" \
1022         FW_BUG "If that doesn't help, try upgrading your BIOS.\n"
1023 
1024 /* per CPU init entry point to the driver */
1025 static int powernowk8_cpu_init(struct cpufreq_policy *pol)
1026 {
1027         struct powernow_k8_data *data;
1028         struct init_on_cpu init_on_cpu;
1029         int rc, cpu;
1030 
1031         smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1);
1032         if (rc)
1033                 return -ENODEV;
1034 
1035         data = kzalloc(sizeof(*data), GFP_KERNEL);
1036         if (!data)
1037                 return -ENOMEM;
1038 
1039         data->cpu = pol->cpu;
1040 
1041         if (powernow_k8_cpu_init_acpi(data)) {
1042                 /*
1043                  * Use the PSB BIOS structure. This is only available on
1044                  * an UP version, and is deprecated by AMD.
1045                  */
1046                 if (num_online_cpus() != 1) {
1047                         pr_err_once(MISSING_PSS_MSG);
1048                         goto err_out;
1049                 }
1050                 if (pol->cpu != 0) {
1051                         pr_err(FW_BUG "No ACPI _PSS objects for CPU other than CPU0. Complain to your BIOS vendor.\n");
1052                         goto err_out;
1053                 }
1054                 rc = find_psb_table(data);
1055                 if (rc)
1056                         goto err_out;
1057 
1058                 /* Take a crude guess here.
1059                  * That guess was in microseconds, so multiply with 1000 */
1060                 pol->cpuinfo.transition_latency = (
1061                          ((data->rvo + 8) * data->vstable * VST_UNITS_20US) +
1062                          ((1 << data->irt) * 30)) * 1000;
1063         } else /* ACPI _PSS objects available */
1064                 pol->cpuinfo.transition_latency = get_transition_latency(data);
1065 
1066         /* only run on specific CPU from here on */
1067         init_on_cpu.data = data;
1068         smp_call_function_single(data->cpu, powernowk8_cpu_init_on_cpu,
1069                                  &init_on_cpu, 1);
1070         rc = init_on_cpu.rc;
1071         if (rc != 0)
1072                 goto err_out_exit_acpi;
1073 
1074         cpumask_copy(pol->cpus, topology_core_cpumask(pol->cpu));
1075         data->available_cores = pol->cpus;
1076         pol->freq_table = data->powernow_table;
1077 
1078         pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n",
1079                 data->currfid, data->currvid);
1080 
1081         /* Point all the CPUs in this policy to the same data */
1082         for_each_cpu(cpu, pol->cpus)
1083                 per_cpu(powernow_data, cpu) = data;
1084 
1085         return 0;
1086 
1087 err_out_exit_acpi:
1088         powernow_k8_cpu_exit_acpi(data);
1089 
1090 err_out:
1091         kfree(data);
1092         return -ENODEV;
1093 }
1094 
1095 static int powernowk8_cpu_exit(struct cpufreq_policy *pol)
1096 {
1097         struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
1098         int cpu;
1099 
1100         if (!data)
1101                 return -EINVAL;
1102 
1103         powernow_k8_cpu_exit_acpi(data);
1104 
1105         kfree(data->powernow_table);
1106         kfree(data);
1107         for_each_cpu(cpu, pol->cpus)
1108                 per_cpu(powernow_data, cpu) = NULL;
1109 
1110         return 0;
1111 }
1112 
1113 static void query_values_on_cpu(void *_err)
1114 {
1115         int *err = _err;
1116         struct powernow_k8_data *data = __this_cpu_read(powernow_data);
1117 
1118         *err = query_current_values_with_pending_wait(data);
1119 }
1120 
1121 static unsigned int powernowk8_get(unsigned int cpu)
1122 {
1123         struct powernow_k8_data *data = per_cpu(powernow_data, cpu);
1124         unsigned int khz = 0;
1125         int err;
1126 
1127         if (!data)
1128                 return 0;
1129 
1130         smp_call_function_single(cpu, query_values_on_cpu, &err, true);
1131         if (err)
1132                 goto out;
1133 
1134         khz = find_khz_freq_from_fid(data->currfid);
1135 
1136 
1137 out:
1138         return khz;
1139 }
1140 
1141 static struct cpufreq_driver cpufreq_amd64_driver = {
1142         .flags          = CPUFREQ_ASYNC_NOTIFICATION,
1143         .verify         = cpufreq_generic_frequency_table_verify,
1144         .target_index   = powernowk8_target,
1145         .bios_limit     = acpi_processor_get_bios_limit,
1146         .init           = powernowk8_cpu_init,
1147         .exit           = powernowk8_cpu_exit,
1148         .get            = powernowk8_get,
1149         .name           = "powernow-k8",
1150         .attr           = cpufreq_generic_attr,
1151 };
1152 
1153 static void __request_acpi_cpufreq(void)
1154 {
1155         const char drv[] = "acpi-cpufreq";
1156         const char *cur_drv;
1157 
1158         cur_drv = cpufreq_get_current_driver();
1159         if (!cur_drv)
1160                 goto request;
1161 
1162         if (strncmp(cur_drv, drv, min_t(size_t, strlen(cur_drv), strlen(drv))))
1163                 pr_warn("WTF driver: %s\n", cur_drv);
1164 
1165         return;
1166 
1167  request:
1168         pr_warn("This CPU is not supported anymore, using acpi-cpufreq instead.\n");
1169         request_module(drv);
1170 }
1171 
1172 /* driver entry point for init */
1173 static int powernowk8_init(void)
1174 {
1175         unsigned int i, supported_cpus = 0;
1176         int ret;
1177 
1178         if (boot_cpu_has(X86_FEATURE_HW_PSTATE)) {
1179                 __request_acpi_cpufreq();
1180                 return -ENODEV;
1181         }
1182 
1183         if (!x86_match_cpu(powernow_k8_ids))
1184                 return -ENODEV;
1185 
1186         get_online_cpus();
1187         for_each_online_cpu(i) {
1188                 smp_call_function_single(i, check_supported_cpu, &ret, 1);
1189                 if (!ret)
1190                         supported_cpus++;
1191         }
1192 
1193         if (supported_cpus != num_online_cpus()) {
1194                 put_online_cpus();
1195                 return -ENODEV;
1196         }
1197         put_online_cpus();
1198 
1199         ret = cpufreq_register_driver(&cpufreq_amd64_driver);
1200         if (ret)
1201                 return ret;
1202 
1203         pr_info("Found %d %s (%d cpu cores) (" VERSION ")\n",
1204                 num_online_nodes(), boot_cpu_data.x86_model_id, supported_cpus);
1205 
1206         return ret;
1207 }
1208 
1209 /* driver entry point for term */
1210 static void __exit powernowk8_exit(void)
1211 {
1212         pr_debug("exit\n");
1213 
1214         cpufreq_unregister_driver(&cpufreq_amd64_driver);
1215 }
1216 
1217 MODULE_AUTHOR("Paul Devriendt <paul.devriendt@amd.com>");
1218 MODULE_AUTHOR("Mark Langsdorf <mark.langsdorf@amd.com>");
1219 MODULE_DESCRIPTION("AMD Athlon 64 and Opteron processor frequency driver.");
1220 MODULE_LICENSE("GPL");
1221 
1222 late_initcall(powernowk8_init);
1223 module_exit(powernowk8_exit);
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/cpufreq/powernow-k8.c

DEFINITIONS
