root/drivers/cpufreq/acpi-cpufreq.c

DEFINITIONS

1. to_perf_data
2. boost_state
3. boost_set_msr
4. boost_set_msr_each
5. set_boost
6. show_freqdomain_cpus
7. store_cpb
8. show_cpb
9. check_est_cpu
10. check_amd_hwpstate_cpu
11. extract_io
12. extract_msr
13. extract_freq
14. cpu_freq_read_intel
15. cpu_freq_write_intel
16. cpu_freq_read_amd
17. cpu_freq_write_amd
18. cpu_freq_read_io
19. cpu_freq_write_io
20. do_drv_read
21. drv_read
22. do_drv_write
23. drv_write
24. get_cur_val
25. get_cur_freq_on_cpu
26. check_freqs
27. acpi_cpufreq_target
28. acpi_cpufreq_fast_switch
29. acpi_cpufreq_guess_freq
30. free_acpi_perf_data
31. cpufreq_boost_online
32. cpufreq_boost_down_prep
33. acpi_cpufreq_early_init
34. sw_any_bug_found
35. acpi_cpufreq_blacklist
36. acpi_cpufreq_cpu_init
37. acpi_cpufreq_cpu_exit
38. acpi_cpufreq_cpu_ready
39. acpi_cpufreq_resume
40. acpi_cpufreq_boost_init
41. acpi_cpufreq_boost_exit
42. acpi_cpufreq_init
43. acpi_cpufreq_exit

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * acpi-cpufreq.c - ACPI Processor P-States Driver
   4  *
   5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   7  *  Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
   8  *  Copyright (C) 2006       Denis Sadykov <denis.m.sadykov@intel.com>
   9  */
  10 
  11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12 
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/smp.h>
  17 #include <linux/sched.h>
  18 #include <linux/cpufreq.h>
  19 #include <linux/compiler.h>
  20 #include <linux/dmi.h>
  21 #include <linux/slab.h>
  22 
  23 #include <linux/acpi.h>
  24 #include <linux/io.h>
  25 #include <linux/delay.h>
  26 #include <linux/uaccess.h>
  27 
  28 #include <acpi/processor.h>
  29 
  30 #include <asm/msr.h>
  31 #include <asm/processor.h>
  32 #include <asm/cpufeature.h>
  33 
  34 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
  35 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
  36 MODULE_LICENSE("GPL");
  37 
  38 enum {
  39         UNDEFINED_CAPABLE = 0,
  40         SYSTEM_INTEL_MSR_CAPABLE,
  41         SYSTEM_AMD_MSR_CAPABLE,
  42         SYSTEM_IO_CAPABLE,
  43 };
  44 
  45 #define INTEL_MSR_RANGE         (0xffff)
  46 #define AMD_MSR_RANGE           (0x7)
  47 #define HYGON_MSR_RANGE         (0x7)
  48 
  49 #define MSR_K7_HWCR_CPB_DIS     (1ULL << 25)
  50 
  51 struct acpi_cpufreq_data {
  52         unsigned int resume;
  53         unsigned int cpu_feature;
  54         unsigned int acpi_perf_cpu;
  55         cpumask_var_t freqdomain_cpus;
  56         void (*cpu_freq_write)(struct acpi_pct_register *reg, u32 val);
  57         u32 (*cpu_freq_read)(struct acpi_pct_register *reg);
  58 };
  59 
  60 /* acpi_perf_data is a pointer to percpu data. */
  61 static struct acpi_processor_performance __percpu *acpi_perf_data;
  62 
  63 static inline struct acpi_processor_performance *to_perf_data(struct acpi_cpufreq_data *data)
  64 {
  65         return per_cpu_ptr(acpi_perf_data, data->acpi_perf_cpu);
  66 }
  67 
  68 static struct cpufreq_driver acpi_cpufreq_driver;
  69 
  70 static unsigned int acpi_pstate_strict;
  71 
  72 static bool boost_state(unsigned int cpu)
  73 {
  74         u32 lo, hi;
  75         u64 msr;
  76 
  77         switch (boot_cpu_data.x86_vendor) {
  78         case X86_VENDOR_INTEL:
  79                 rdmsr_on_cpu(cpu, MSR_IA32_MISC_ENABLE, &lo, &hi);
  80                 msr = lo | ((u64)hi << 32);
  81                 return !(msr & MSR_IA32_MISC_ENABLE_TURBO_DISABLE);
  82         case X86_VENDOR_HYGON:
  83         case X86_VENDOR_AMD:
  84                 rdmsr_on_cpu(cpu, MSR_K7_HWCR, &lo, &hi);
  85                 msr = lo | ((u64)hi << 32);
  86                 return !(msr & MSR_K7_HWCR_CPB_DIS);
  87         }
  88         return false;
  89 }
  90 
  91 static int boost_set_msr(bool enable)
  92 {
  93         u32 msr_addr;
  94         u64 msr_mask, val;
  95 
  96         switch (boot_cpu_data.x86_vendor) {
  97         case X86_VENDOR_INTEL:
  98                 msr_addr = MSR_IA32_MISC_ENABLE;
  99                 msr_mask = MSR_IA32_MISC_ENABLE_TURBO_DISABLE;
 100                 break;
 101         case X86_VENDOR_HYGON:
 102         case X86_VENDOR_AMD:
 103                 msr_addr = MSR_K7_HWCR;
 104                 msr_mask = MSR_K7_HWCR_CPB_DIS;
 105                 break;
 106         default:
 107                 return -EINVAL;
 108         }
 109 
 110         rdmsrl(msr_addr, val);
 111 
 112         if (enable)
 113                 val &= ~msr_mask;
 114         else
 115                 val |= msr_mask;
 116 
 117         wrmsrl(msr_addr, val);
 118         return 0;
 119 }
 120 
 121 static void boost_set_msr_each(void *p_en)
 122 {
 123         bool enable = (bool) p_en;
 124 
 125         boost_set_msr(enable);
 126 }
 127 
 128 static int set_boost(int val)
 129 {
 130         get_online_cpus();
 131         on_each_cpu(boost_set_msr_each, (void *)(long)val, 1);
 132         put_online_cpus();
 133         pr_debug("Core Boosting %sabled.\n", val ? "en" : "dis");
 134 
 135         return 0;
 136 }
 137 
 138 static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
 139 {
 140         struct acpi_cpufreq_data *data = policy->driver_data;
 141 
 142         if (unlikely(!data))
 143                 return -ENODEV;
 144 
 145         return cpufreq_show_cpus(data->freqdomain_cpus, buf);
 146 }
 147 
 148 cpufreq_freq_attr_ro(freqdomain_cpus);
 149 
 150 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
 151 static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf,
 152                          size_t count)
 153 {
 154         int ret;
 155         unsigned int val = 0;
 156 
 157         if (!acpi_cpufreq_driver.set_boost)
 158                 return -EINVAL;
 159 
 160         ret = kstrtouint(buf, 10, &val);
 161         if (ret || val > 1)
 162                 return -EINVAL;
 163 
 164         set_boost(val);
 165 
 166         return count;
 167 }
 168 
 169 static ssize_t show_cpb(struct cpufreq_policy *policy, char *buf)
 170 {
 171         return sprintf(buf, "%u\n", acpi_cpufreq_driver.boost_enabled);
 172 }
 173 
 174 cpufreq_freq_attr_rw(cpb);
 175 #endif
 176 
 177 static int check_est_cpu(unsigned int cpuid)
 178 {
 179         struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
 180 
 181         return cpu_has(cpu, X86_FEATURE_EST);
 182 }
 183 
 184 static int check_amd_hwpstate_cpu(unsigned int cpuid)
 185 {
 186         struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
 187 
 188         return cpu_has(cpu, X86_FEATURE_HW_PSTATE);
 189 }
 190 
 191 static unsigned extract_io(struct cpufreq_policy *policy, u32 value)
 192 {
 193         struct acpi_cpufreq_data *data = policy->driver_data;
 194         struct acpi_processor_performance *perf;
 195         int i;
 196 
 197         perf = to_perf_data(data);
 198 
 199         for (i = 0; i < perf->state_count; i++) {
 200                 if (value == perf->states[i].status)
 201                         return policy->freq_table[i].frequency;
 202         }
 203         return 0;
 204 }
 205 
 206 static unsigned extract_msr(struct cpufreq_policy *policy, u32 msr)
 207 {
 208         struct acpi_cpufreq_data *data = policy->driver_data;
 209         struct cpufreq_frequency_table *pos;
 210         struct acpi_processor_performance *perf;
 211 
 212         if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
 213                 msr &= AMD_MSR_RANGE;
 214         else if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
 215                 msr &= HYGON_MSR_RANGE;
 216         else
 217                 msr &= INTEL_MSR_RANGE;
 218 
 219         perf = to_perf_data(data);
 220 
 221         cpufreq_for_each_entry(pos, policy->freq_table)
 222                 if (msr == perf->states[pos->driver_data].status)
 223                         return pos->frequency;
 224         return policy->freq_table[0].frequency;
 225 }
 226 
 227 static unsigned extract_freq(struct cpufreq_policy *policy, u32 val)
 228 {
 229         struct acpi_cpufreq_data *data = policy->driver_data;
 230 
 231         switch (data->cpu_feature) {
 232         case SYSTEM_INTEL_MSR_CAPABLE:
 233         case SYSTEM_AMD_MSR_CAPABLE:
 234                 return extract_msr(policy, val);
 235         case SYSTEM_IO_CAPABLE:
 236                 return extract_io(policy, val);
 237         default:
 238                 return 0;
 239         }
 240 }
 241 
 242 static u32 cpu_freq_read_intel(struct acpi_pct_register *not_used)
 243 {
 244         u32 val, dummy;
 245 
 246         rdmsr(MSR_IA32_PERF_CTL, val, dummy);
 247         return val;
 248 }
 249 
 250 static void cpu_freq_write_intel(struct acpi_pct_register *not_used, u32 val)
 251 {
 252         u32 lo, hi;
 253 
 254         rdmsr(MSR_IA32_PERF_CTL, lo, hi);
 255         lo = (lo & ~INTEL_MSR_RANGE) | (val & INTEL_MSR_RANGE);
 256         wrmsr(MSR_IA32_PERF_CTL, lo, hi);
 257 }
 258 
 259 static u32 cpu_freq_read_amd(struct acpi_pct_register *not_used)
 260 {
 261         u32 val, dummy;
 262 
 263         rdmsr(MSR_AMD_PERF_CTL, val, dummy);
 264         return val;
 265 }
 266 
 267 static void cpu_freq_write_amd(struct acpi_pct_register *not_used, u32 val)
 268 {
 269         wrmsr(MSR_AMD_PERF_CTL, val, 0);
 270 }
 271 
 272 static u32 cpu_freq_read_io(struct acpi_pct_register *reg)
 273 {
 274         u32 val;
 275 
 276         acpi_os_read_port(reg->address, &val, reg->bit_width);
 277         return val;
 278 }
 279 
 280 static void cpu_freq_write_io(struct acpi_pct_register *reg, u32 val)
 281 {
 282         acpi_os_write_port(reg->address, val, reg->bit_width);
 283 }
 284 
 285 struct drv_cmd {
 286         struct acpi_pct_register *reg;
 287         u32 val;
 288         union {
 289                 void (*write)(struct acpi_pct_register *reg, u32 val);
 290                 u32 (*read)(struct acpi_pct_register *reg);
 291         } func;
 292 };
 293 
 294 /* Called via smp_call_function_single(), on the target CPU */
 295 static void do_drv_read(void *_cmd)
 296 {
 297         struct drv_cmd *cmd = _cmd;
 298 
 299         cmd->val = cmd->func.read(cmd->reg);
 300 }
 301 
 302 static u32 drv_read(struct acpi_cpufreq_data *data, const struct cpumask *mask)
 303 {
 304         struct acpi_processor_performance *perf = to_perf_data(data);
 305         struct drv_cmd cmd = {
 306                 .reg = &perf->control_register,
 307                 .func.read = data->cpu_freq_read,
 308         };
 309         int err;
 310 
 311         err = smp_call_function_any(mask, do_drv_read, &cmd, 1);
 312         WARN_ON_ONCE(err);      /* smp_call_function_any() was buggy? */
 313         return cmd.val;
 314 }
 315 
 316 /* Called via smp_call_function_many(), on the target CPUs */
 317 static void do_drv_write(void *_cmd)
 318 {
 319         struct drv_cmd *cmd = _cmd;
 320 
 321         cmd->func.write(cmd->reg, cmd->val);
 322 }
 323 
 324 static void drv_write(struct acpi_cpufreq_data *data,
 325                       const struct cpumask *mask, u32 val)
 326 {
 327         struct acpi_processor_performance *perf = to_perf_data(data);
 328         struct drv_cmd cmd = {
 329                 .reg = &perf->control_register,
 330                 .val = val,
 331                 .func.write = data->cpu_freq_write,
 332         };
 333         int this_cpu;
 334 
 335         this_cpu = get_cpu();
 336         if (cpumask_test_cpu(this_cpu, mask))
 337                 do_drv_write(&cmd);
 338 
 339         smp_call_function_many(mask, do_drv_write, &cmd, 1);
 340         put_cpu();
 341 }
 342 
 343 static u32 get_cur_val(const struct cpumask *mask, struct acpi_cpufreq_data *data)
 344 {
 345         u32 val;
 346 
 347         if (unlikely(cpumask_empty(mask)))
 348                 return 0;
 349 
 350         val = drv_read(data, mask);
 351 
 352         pr_debug("%s = %u\n", __func__, val);
 353 
 354         return val;
 355 }
 356 
 357 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 358 {
 359         struct acpi_cpufreq_data *data;
 360         struct cpufreq_policy *policy;
 361         unsigned int freq;
 362         unsigned int cached_freq;
 363 
 364         pr_debug("%s (%d)\n", __func__, cpu);
 365 
 366         policy = cpufreq_cpu_get_raw(cpu);
 367         if (unlikely(!policy))
 368                 return 0;
 369 
 370         data = policy->driver_data;
 371         if (unlikely(!data || !policy->freq_table))
 372                 return 0;
 373 
 374         cached_freq = policy->freq_table[to_perf_data(data)->state].frequency;
 375         freq = extract_freq(policy, get_cur_val(cpumask_of(cpu), data));
 376         if (freq != cached_freq) {
 377                 /*
 378                  * The dreaded BIOS frequency change behind our back.
 379                  * Force set the frequency on next target call.
 380                  */
 381                 data->resume = 1;
 382         }
 383 
 384         pr_debug("cur freq = %u\n", freq);
 385 
 386         return freq;
 387 }
 388 
 389 static unsigned int check_freqs(struct cpufreq_policy *policy,
 390                                 const struct cpumask *mask, unsigned int freq)
 391 {
 392         struct acpi_cpufreq_data *data = policy->driver_data;
 393         unsigned int cur_freq;
 394         unsigned int i;
 395 
 396         for (i = 0; i < 100; i++) {
 397                 cur_freq = extract_freq(policy, get_cur_val(mask, data));
 398                 if (cur_freq == freq)
 399                         return 1;
 400                 udelay(10);
 401         }
 402         return 0;
 403 }
 404 
 405 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 406                                unsigned int index)
 407 {
 408         struct acpi_cpufreq_data *data = policy->driver_data;
 409         struct acpi_processor_performance *perf;
 410         const struct cpumask *mask;
 411         unsigned int next_perf_state = 0; /* Index into perf table */
 412         int result = 0;
 413 
 414         if (unlikely(!data)) {
 415                 return -ENODEV;
 416         }
 417 
 418         perf = to_perf_data(data);
 419         next_perf_state = policy->freq_table[index].driver_data;
 420         if (perf->state == next_perf_state) {
 421                 if (unlikely(data->resume)) {
 422                         pr_debug("Called after resume, resetting to P%d\n",
 423                                 next_perf_state);
 424                         data->resume = 0;
 425                 } else {
 426                         pr_debug("Already at target state (P%d)\n",
 427                                 next_perf_state);
 428                         return 0;
 429                 }
 430         }
 431 
 432         /*
 433          * The core won't allow CPUs to go away until the governor has been
 434          * stopped, so we can rely on the stability of policy->cpus.
 435          */
 436         mask = policy->shared_type == CPUFREQ_SHARED_TYPE_ANY ?
 437                 cpumask_of(policy->cpu) : policy->cpus;
 438 
 439         drv_write(data, mask, perf->states[next_perf_state].control);
 440 
 441         if (acpi_pstate_strict) {
 442                 if (!check_freqs(policy, mask,
 443                                  policy->freq_table[index].frequency)) {
 444                         pr_debug("%s (%d)\n", __func__, policy->cpu);
 445                         result = -EAGAIN;
 446                 }
 447         }
 448 
 449         if (!result)
 450                 perf->state = next_perf_state;
 451 
 452         return result;
 453 }
 454 
 455 static unsigned int acpi_cpufreq_fast_switch(struct cpufreq_policy *policy,
 456                                              unsigned int target_freq)
 457 {
 458         struct acpi_cpufreq_data *data = policy->driver_data;
 459         struct acpi_processor_performance *perf;
 460         struct cpufreq_frequency_table *entry;
 461         unsigned int next_perf_state, next_freq, index;
 462 
 463         /*
 464          * Find the closest frequency above target_freq.
 465          */
 466         if (policy->cached_target_freq == target_freq)
 467                 index = policy->cached_resolved_idx;
 468         else
 469                 index = cpufreq_table_find_index_dl(policy, target_freq);
 470 
 471         entry = &policy->freq_table[index];
 472         next_freq = entry->frequency;
 473         next_perf_state = entry->driver_data;
 474 
 475         perf = to_perf_data(data);
 476         if (perf->state == next_perf_state) {
 477                 if (unlikely(data->resume))
 478                         data->resume = 0;
 479                 else
 480                         return next_freq;
 481         }
 482 
 483         data->cpu_freq_write(&perf->control_register,
 484                              perf->states[next_perf_state].control);
 485         perf->state = next_perf_state;
 486         return next_freq;
 487 }
 488 
 489 static unsigned long
 490 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
 491 {
 492         struct acpi_processor_performance *perf;
 493 
 494         perf = to_perf_data(data);
 495         if (cpu_khz) {
 496                 /* search the closest match to cpu_khz */
 497                 unsigned int i;
 498                 unsigned long freq;
 499                 unsigned long freqn = perf->states[0].core_frequency * 1000;
 500 
 501                 for (i = 0; i < (perf->state_count-1); i++) {
 502                         freq = freqn;
 503                         freqn = perf->states[i+1].core_frequency * 1000;
 504                         if ((2 * cpu_khz) > (freqn + freq)) {
 505                                 perf->state = i;
 506                                 return freq;
 507                         }
 508                 }
 509                 perf->state = perf->state_count-1;
 510                 return freqn;
 511         } else {
 512                 /* assume CPU is at P0... */
 513                 perf->state = 0;
 514                 return perf->states[0].core_frequency * 1000;
 515         }
 516 }
 517 
 518 static void free_acpi_perf_data(void)
 519 {
 520         unsigned int i;
 521 
 522         /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
 523         for_each_possible_cpu(i)
 524                 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
 525                                  ->shared_cpu_map);
 526         free_percpu(acpi_perf_data);
 527 }
 528 
 529 static int cpufreq_boost_online(unsigned int cpu)
 530 {
 531         /*
 532          * On the CPU_UP path we simply keep the boost-disable flag
 533          * in sync with the current global state.
 534          */
 535         return boost_set_msr(acpi_cpufreq_driver.boost_enabled);
 536 }
 537 
 538 static int cpufreq_boost_down_prep(unsigned int cpu)
 539 {
 540         /*
 541          * Clear the boost-disable bit on the CPU_DOWN path so that
 542          * this cpu cannot block the remaining ones from boosting.
 543          */
 544         return boost_set_msr(1);
 545 }
 546 
 547 /*
 548  * acpi_cpufreq_early_init - initialize ACPI P-States library
 549  *
 550  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
 551  * in order to determine correct frequency and voltage pairings. We can
 552  * do _PDC and _PSD and find out the processor dependency for the
 553  * actual init that will happen later...
 554  */
 555 static int __init acpi_cpufreq_early_init(void)
 556 {
 557         unsigned int i;
 558         pr_debug("%s\n", __func__);
 559 
 560         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
 561         if (!acpi_perf_data) {
 562                 pr_debug("Memory allocation error for acpi_perf_data.\n");
 563                 return -ENOMEM;
 564         }
 565         for_each_possible_cpu(i) {
 566                 if (!zalloc_cpumask_var_node(
 567                         &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
 568                         GFP_KERNEL, cpu_to_node(i))) {
 569 
 570                         /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
 571                         free_acpi_perf_data();
 572                         return -ENOMEM;
 573                 }
 574         }
 575 
 576         /* Do initialization in ACPI core */
 577         acpi_processor_preregister_performance(acpi_perf_data);
 578         return 0;
 579 }
 580 
 581 #ifdef CONFIG_SMP
 582 /*
 583  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
 584  * or do it in BIOS firmware and won't inform about it to OS. If not
 585  * detected, this has a side effect of making CPU run at a different speed
 586  * than OS intended it to run at. Detect it and handle it cleanly.
 587  */
 588 static int bios_with_sw_any_bug;
 589 
 590 static int sw_any_bug_found(const struct dmi_system_id *d)
 591 {
 592         bios_with_sw_any_bug = 1;
 593         return 0;
 594 }
 595 
 596 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
 597         {
 598                 .callback = sw_any_bug_found,
 599                 .ident = "Supermicro Server X6DLP",
 600                 .matches = {
 601                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
 602                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
 603                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
 604                 },
 605         },
 606         { }
 607 };
 608 
 609 static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
 610 {
 611         /* Intel Xeon Processor 7100 Series Specification Update
 612          * http://www.intel.com/Assets/PDF/specupdate/314554.pdf
 613          * AL30: A Machine Check Exception (MCE) Occurring during an
 614          * Enhanced Intel SpeedStep Technology Ratio Change May Cause
 615          * Both Processor Cores to Lock Up. */
 616         if (c->x86_vendor == X86_VENDOR_INTEL) {
 617                 if ((c->x86 == 15) &&
 618                     (c->x86_model == 6) &&
 619                     (c->x86_stepping == 8)) {
 620                         pr_info("Intel(R) Xeon(R) 7100 Errata AL30, processors may lock up on frequency changes: disabling acpi-cpufreq\n");
 621                         return -ENODEV;
 622                     }
 623                 }
 624         return 0;
 625 }
 626 #endif
 627 
 628 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 629 {
 630         unsigned int i;
 631         unsigned int valid_states = 0;
 632         unsigned int cpu = policy->cpu;
 633         struct acpi_cpufreq_data *data;
 634         unsigned int result = 0;
 635         struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
 636         struct acpi_processor_performance *perf;
 637         struct cpufreq_frequency_table *freq_table;
 638 #ifdef CONFIG_SMP
 639         static int blacklisted;
 640 #endif
 641 
 642         pr_debug("%s\n", __func__);
 643 
 644 #ifdef CONFIG_SMP
 645         if (blacklisted)
 646                 return blacklisted;
 647         blacklisted = acpi_cpufreq_blacklist(c);
 648         if (blacklisted)
 649                 return blacklisted;
 650 #endif
 651 
 652         data = kzalloc(sizeof(*data), GFP_KERNEL);
 653         if (!data)
 654                 return -ENOMEM;
 655 
 656         if (!zalloc_cpumask_var(&data->freqdomain_cpus, GFP_KERNEL)) {
 657                 result = -ENOMEM;
 658                 goto err_free;
 659         }
 660 
 661         perf = per_cpu_ptr(acpi_perf_data, cpu);
 662         data->acpi_perf_cpu = cpu;
 663         policy->driver_data = data;
 664 
 665         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
 666                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
 667 
 668         result = acpi_processor_register_performance(perf, cpu);
 669         if (result)
 670                 goto err_free_mask;
 671 
 672         policy->shared_type = perf->shared_type;
 673 
 674         /*
 675          * Will let policy->cpus know about dependency only when software
 676          * coordination is required.
 677          */
 678         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
 679             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
 680                 cpumask_copy(policy->cpus, perf->shared_cpu_map);
 681         }
 682         cpumask_copy(data->freqdomain_cpus, perf->shared_cpu_map);
 683 
 684 #ifdef CONFIG_SMP
 685         dmi_check_system(sw_any_bug_dmi_table);
 686         if (bios_with_sw_any_bug && !policy_is_shared(policy)) {
 687                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 688                 cpumask_copy(policy->cpus, topology_core_cpumask(cpu));
 689         }
 690 
 691         if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
 692                 cpumask_clear(policy->cpus);
 693                 cpumask_set_cpu(cpu, policy->cpus);
 694                 cpumask_copy(data->freqdomain_cpus,
 695                              topology_sibling_cpumask(cpu));
 696                 policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
 697                 pr_info_once("overriding BIOS provided _PSD data\n");
 698         }
 699 #endif
 700 
 701         /* capability check */
 702         if (perf->state_count <= 1) {
 703                 pr_debug("No P-States\n");
 704                 result = -ENODEV;
 705                 goto err_unreg;
 706         }
 707 
 708         if (perf->control_register.space_id != perf->status_register.space_id) {
 709                 result = -ENODEV;
 710                 goto err_unreg;
 711         }
 712 
 713         switch (perf->control_register.space_id) {
 714         case ACPI_ADR_SPACE_SYSTEM_IO:
 715                 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
 716                     boot_cpu_data.x86 == 0xf) {
 717                         pr_debug("AMD K8 systems must use native drivers.\n");
 718                         result = -ENODEV;
 719                         goto err_unreg;
 720                 }
 721                 pr_debug("SYSTEM IO addr space\n");
 722                 data->cpu_feature = SYSTEM_IO_CAPABLE;
 723                 data->cpu_freq_read = cpu_freq_read_io;
 724                 data->cpu_freq_write = cpu_freq_write_io;
 725                 break;
 726         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 727                 pr_debug("HARDWARE addr space\n");
 728                 if (check_est_cpu(cpu)) {
 729                         data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
 730                         data->cpu_freq_read = cpu_freq_read_intel;
 731                         data->cpu_freq_write = cpu_freq_write_intel;
 732                         break;
 733                 }
 734                 if (check_amd_hwpstate_cpu(cpu)) {
 735                         data->cpu_feature = SYSTEM_AMD_MSR_CAPABLE;
 736                         data->cpu_freq_read = cpu_freq_read_amd;
 737                         data->cpu_freq_write = cpu_freq_write_amd;
 738                         break;
 739                 }
 740                 result = -ENODEV;
 741                 goto err_unreg;
 742         default:
 743                 pr_debug("Unknown addr space %d\n",
 744                         (u32) (perf->control_register.space_id));
 745                 result = -ENODEV;
 746                 goto err_unreg;
 747         }
 748 
 749         freq_table = kcalloc(perf->state_count + 1, sizeof(*freq_table),
 750                              GFP_KERNEL);
 751         if (!freq_table) {
 752                 result = -ENOMEM;
 753                 goto err_unreg;
 754         }
 755 
 756         /* detect transition latency */
 757         policy->cpuinfo.transition_latency = 0;
 758         for (i = 0; i < perf->state_count; i++) {
 759                 if ((perf->states[i].transition_latency * 1000) >
 760                     policy->cpuinfo.transition_latency)
 761                         policy->cpuinfo.transition_latency =
 762                             perf->states[i].transition_latency * 1000;
 763         }
 764 
 765         /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
 766         if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
 767             policy->cpuinfo.transition_latency > 20 * 1000) {
 768                 policy->cpuinfo.transition_latency = 20 * 1000;
 769                 pr_info_once("P-state transition latency capped at 20 uS\n");
 770         }
 771 
 772         /* table init */
 773         for (i = 0; i < perf->state_count; i++) {
 774                 if (i > 0 && perf->states[i].core_frequency >=
 775                     freq_table[valid_states-1].frequency / 1000)
 776                         continue;
 777 
 778                 freq_table[valid_states].driver_data = i;
 779                 freq_table[valid_states].frequency =
 780                     perf->states[i].core_frequency * 1000;
 781                 valid_states++;
 782         }
 783         freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
 784         policy->freq_table = freq_table;
 785         perf->state = 0;
 786 
 787         switch (perf->control_register.space_id) {
 788         case ACPI_ADR_SPACE_SYSTEM_IO:
 789                 /*
 790                  * The core will not set policy->cur, because
 791                  * cpufreq_driver->get is NULL, so we need to set it here.
 792                  * However, we have to guess it, because the current speed is
 793                  * unknown and not detectable via IO ports.
 794                  */
 795                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
 796                 break;
 797         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 798                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
 799                 break;
 800         default:
 801                 break;
 802         }
 803 
 804         /* notify BIOS that we exist */
 805         acpi_processor_notify_smm(THIS_MODULE);
 806 
 807         pr_debug("CPU%u - ACPI performance management activated.\n", cpu);
 808         for (i = 0; i < perf->state_count; i++)
 809                 pr_debug("     %cP%d: %d MHz, %d mW, %d uS\n",
 810                         (i == perf->state ? '*' : ' '), i,
 811                         (u32) perf->states[i].core_frequency,
 812                         (u32) perf->states[i].power,
 813                         (u32) perf->states[i].transition_latency);
 814 
 815         /*
 816          * the first call to ->target() should result in us actually
 817          * writing something to the appropriate registers.
 818          */
 819         data->resume = 1;
 820 
 821         policy->fast_switch_possible = !acpi_pstate_strict &&
 822                 !(policy_is_shared(policy) && policy->shared_type != CPUFREQ_SHARED_TYPE_ANY);
 823 
 824         return result;
 825 
 826 err_unreg:
 827         acpi_processor_unregister_performance(cpu);
 828 err_free_mask:
 829         free_cpumask_var(data->freqdomain_cpus);
 830 err_free:
 831         kfree(data);
 832         policy->driver_data = NULL;
 833 
 834         return result;
 835 }
 836 
 837 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 838 {
 839         struct acpi_cpufreq_data *data = policy->driver_data;
 840 
 841         pr_debug("%s\n", __func__);
 842 
 843         policy->fast_switch_possible = false;
 844         policy->driver_data = NULL;
 845         acpi_processor_unregister_performance(data->acpi_perf_cpu);
 846         free_cpumask_var(data->freqdomain_cpus);
 847         kfree(policy->freq_table);
 848         kfree(data);
 849 
 850         return 0;
 851 }
 852 
 853 static void acpi_cpufreq_cpu_ready(struct cpufreq_policy *policy)
 854 {
 855         struct acpi_processor_performance *perf = per_cpu_ptr(acpi_perf_data,
 856                                                               policy->cpu);
 857 
 858         if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
 859                 pr_warn(FW_WARN "P-state 0 is not max freq\n");
 860 }
 861 
 862 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
 863 {
 864         struct acpi_cpufreq_data *data = policy->driver_data;
 865 
 866         pr_debug("%s\n", __func__);
 867 
 868         data->resume = 1;
 869 
 870         return 0;
 871 }
 872 
 873 static struct freq_attr *acpi_cpufreq_attr[] = {
 874         &cpufreq_freq_attr_scaling_available_freqs,
 875         &freqdomain_cpus,
 876 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
 877         &cpb,
 878 #endif
 879         NULL,
 880 };
 881 
 882 static struct cpufreq_driver acpi_cpufreq_driver = {
 883         .verify         = cpufreq_generic_frequency_table_verify,
 884         .target_index   = acpi_cpufreq_target,
 885         .fast_switch    = acpi_cpufreq_fast_switch,
 886         .bios_limit     = acpi_processor_get_bios_limit,
 887         .init           = acpi_cpufreq_cpu_init,
 888         .exit           = acpi_cpufreq_cpu_exit,
 889         .ready          = acpi_cpufreq_cpu_ready,
 890         .resume         = acpi_cpufreq_resume,
 891         .name           = "acpi-cpufreq",
 892         .attr           = acpi_cpufreq_attr,
 893 };
 894 
 895 static enum cpuhp_state acpi_cpufreq_online;
 896 
 897 static void __init acpi_cpufreq_boost_init(void)
 898 {
 899         int ret;
 900 
 901         if (!(boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA))) {
 902                 pr_debug("Boost capabilities not present in the processor\n");
 903                 return;
 904         }
 905 
 906         acpi_cpufreq_driver.set_boost = set_boost;
 907         acpi_cpufreq_driver.boost_enabled = boost_state(0);
 908 
 909         /*
 910          * This calls the online callback on all online cpu and forces all
 911          * MSRs to the same value.
 912          */
 913         ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "cpufreq/acpi:online",
 914                                 cpufreq_boost_online, cpufreq_boost_down_prep);
 915         if (ret < 0) {
 916                 pr_err("acpi_cpufreq: failed to register hotplug callbacks\n");
 917                 return;
 918         }
 919         acpi_cpufreq_online = ret;
 920 }
 921 
 922 static void acpi_cpufreq_boost_exit(void)
 923 {
 924         if (acpi_cpufreq_online > 0)
 925                 cpuhp_remove_state_nocalls(acpi_cpufreq_online);
 926 }
 927 
 928 static int __init acpi_cpufreq_init(void)
 929 {
 930         int ret;
 931 
 932         if (acpi_disabled)
 933                 return -ENODEV;
 934 
 935         /* don't keep reloading if cpufreq_driver exists */
 936         if (cpufreq_get_current_driver())
 937                 return -EEXIST;
 938 
 939         pr_debug("%s\n", __func__);
 940 
 941         ret = acpi_cpufreq_early_init();
 942         if (ret)
 943                 return ret;
 944 
 945 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
 946         /* this is a sysfs file with a strange name and an even stranger
 947          * semantic - per CPU instantiation, but system global effect.
 948          * Lets enable it only on AMD CPUs for compatibility reasons and
 949          * only if configured. This is considered legacy code, which
 950          * will probably be removed at some point in the future.
 951          */
 952         if (!check_amd_hwpstate_cpu(0)) {
 953                 struct freq_attr **attr;
 954 
 955                 pr_debug("CPB unsupported, do not expose it\n");
 956 
 957                 for (attr = acpi_cpufreq_attr; *attr; attr++)
 958                         if (*attr == &cpb) {
 959                                 *attr = NULL;
 960                                 break;
 961                         }
 962         }
 963 #endif
 964         acpi_cpufreq_boost_init();
 965 
 966         ret = cpufreq_register_driver(&acpi_cpufreq_driver);
 967         if (ret) {
 968                 free_acpi_perf_data();
 969                 acpi_cpufreq_boost_exit();
 970         }
 971         return ret;
 972 }
 973 
 974 static void __exit acpi_cpufreq_exit(void)
 975 {
 976         pr_debug("%s\n", __func__);
 977 
 978         acpi_cpufreq_boost_exit();
 979 
 980         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 981 
 982         free_acpi_perf_data();
 983 }
 984 
 985 module_param(acpi_pstate_strict, uint, 0644);
 986 MODULE_PARM_DESC(acpi_pstate_strict,
 987         "value 0 or non-zero. non-zero -> strict ACPI checks are "
 988         "performed during frequency changes.");
 989 
 990 late_initcall(acpi_cpufreq_init);
 991 module_exit(acpi_cpufreq_exit);
 992 
 993 static const struct x86_cpu_id acpi_cpufreq_ids[] = {
 994         X86_FEATURE_MATCH(X86_FEATURE_ACPI),
 995         X86_FEATURE_MATCH(X86_FEATURE_HW_PSTATE),
 996         {}
 997 };
 998 MODULE_DEVICE_TABLE(x86cpu, acpi_cpufreq_ids);
 999 
1000 static const struct acpi_device_id processor_device_ids[] = {
1001         {ACPI_PROCESSOR_OBJECT_HID, },
1002         {ACPI_PROCESSOR_DEVICE_HID, },
1003         {},
1004 };
1005 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
1006 
1007 MODULE_ALIAS("acpi");