1 /* 2 * acpi-cpufreq.c - ACPI Processor P-States Driver 3 * 4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> 5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> 6 * Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de> 7 * Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com> 8 * 9 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 of the License, or (at 14 * your option) any later version. 15 * 16 * This program is distributed in the hope that it will be useful, but 17 * WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 19 * General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License along 22 * with this program; if not, write to the Free Software Foundation, Inc., 23 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. 24 * 25 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 26 */ 27 28 #include <linux/kernel.h> 29 #include <linux/module.h> 30 #include <linux/init.h> 31 #include <linux/smp.h> 32 #include <linux/sched.h> 33 #include <linux/cpufreq.h> 34 #include <linux/compiler.h> 35 #include <linux/dmi.h> 36 #include <linux/slab.h> 37 38 #include <linux/acpi.h> 39 #include <linux/io.h> 40 #include <linux/delay.h> 41 #include <linux/uaccess.h> 42 43 #include <acpi/processor.h> 44 45 #include <asm/msr.h> 46 #include <asm/processor.h> 47 #include <asm/cpufeature.h> 48 #include "mperf.h" 49 50 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski"); 51 MODULE_DESCRIPTION("ACPI Processor P-States Driver"); 52 MODULE_LICENSE("GPL"); 53 54 enum { 55 UNDEFINED_CAPABLE = 0, 56 SYSTEM_INTEL_MSR_CAPABLE, 57 SYSTEM_IO_CAPABLE, 58 }; 59 60 #define INTEL_MSR_RANGE (0xffff) 61 62 struct acpi_cpufreq_data { 63 struct acpi_processor_performance *acpi_data; 64 struct cpufreq_frequency_table *freq_table; 65 unsigned int resume; 66 unsigned int cpu_feature; 67 }; 68 69 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data); 70 71 /* acpi_perf_data is a pointer to percpu data. */ 72 static struct acpi_processor_performance __percpu *acpi_perf_data; 73 74 static struct cpufreq_driver acpi_cpufreq_driver; 75 76 static unsigned int acpi_pstate_strict; 77 78 static int check_est_cpu(unsigned int cpuid) 79 { 80 struct cpuinfo_x86 *cpu = &cpu_data(cpuid); 81 82 return cpu_has(cpu, X86_FEATURE_EST); 83 } 84 85 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data) 86 { 87 struct acpi_processor_performance *perf; 88 int i; 89 90 perf = data->acpi_data; 91 92 for (i = 0; i < perf->state_count; i++) { 93 if (value == perf->states[i].status) 94 return data->freq_table[i].frequency; 95 } 96 return 0; 97 } 98 99 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data) 100 { 101 int i; 102 struct acpi_processor_performance *perf; 103 104 msr &= INTEL_MSR_RANGE; 105 perf = data->acpi_data; 106 107 for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) { 108 if (msr == perf->states[data->freq_table[i].index].status) 109 return data->freq_table[i].frequency; 110 } 111 return data->freq_table[0].frequency; 112 } 113 114 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data) 115 { 116 switch (data->cpu_feature) { 117 case SYSTEM_INTEL_MSR_CAPABLE: 118 return extract_msr(val, data); 119 case SYSTEM_IO_CAPABLE: 120 return extract_io(val, data); 121 default: 122 return 0; 123 } 124 } 125 126 struct msr_addr { 127 u32 reg; 128 }; 129 130 struct io_addr { 131 u16 port; 132 u8 bit_width; 133 }; 134 135 struct drv_cmd { 136 unsigned int type; 137 const struct cpumask *mask; 138 union { 139 struct msr_addr msr; 140 struct io_addr io; 141 } addr; 142 u32 val; 143 }; 144 145 /* Called via smp_call_function_single(), on the target CPU */ 146 static void do_drv_read(void *_cmd) 147 { 148 struct drv_cmd *cmd = _cmd; 149 u32 h; 150 151 switch (cmd->type) { 152 case SYSTEM_INTEL_MSR_CAPABLE: 153 rdmsr(cmd->addr.msr.reg, cmd->val, h); 154 break; 155 case SYSTEM_IO_CAPABLE: 156 acpi_os_read_port((acpi_io_address)cmd->addr.io.port, 157 &cmd->val, 158 (u32)cmd->addr.io.bit_width); 159 break; 160 default: 161 break; 162 } 163 } 164 165 /* Called via smp_call_function_many(), on the target CPUs */ 166 static void do_drv_write(void *_cmd) 167 { 168 struct drv_cmd *cmd = _cmd; 169 u32 lo, hi; 170 171 switch (cmd->type) { 172 case SYSTEM_INTEL_MSR_CAPABLE: 173 rdmsr(cmd->addr.msr.reg, lo, hi); 174 lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE); 175 wrmsr(cmd->addr.msr.reg, lo, hi); 176 break; 177 case SYSTEM_IO_CAPABLE: 178 acpi_os_write_port((acpi_io_address)cmd->addr.io.port, 179 cmd->val, 180 (u32)cmd->addr.io.bit_width); 181 break; 182 default: 183 break; 184 } 185 } 186 187 static void drv_read(struct drv_cmd *cmd) 188 { 189 int err; 190 cmd->val = 0; 191 192 err = smp_call_function_any(cmd->mask, do_drv_read, cmd, 1); 193 WARN_ON_ONCE(err); /* smp_call_function_any() was buggy? */ 194 } 195 196 static void drv_write(struct drv_cmd *cmd) 197 { 198 int this_cpu; 199 200 this_cpu = get_cpu(); 201 if (cpumask_test_cpu(this_cpu, cmd->mask)) 202 do_drv_write(cmd); 203 smp_call_function_many(cmd->mask, do_drv_write, cmd, 1); 204 put_cpu(); 205 } 206 207 static u32 get_cur_val(const struct cpumask *mask) 208 { 209 struct acpi_processor_performance *perf; 210 struct drv_cmd cmd; 211 212 if (unlikely(cpumask_empty(mask))) 213 return 0; 214 215 switch (per_cpu(acfreq_data, cpumask_first(mask))->cpu_feature) { 216 case SYSTEM_INTEL_MSR_CAPABLE: 217 cmd.type = SYSTEM_INTEL_MSR_CAPABLE; 218 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS; 219 break; 220 case SYSTEM_IO_CAPABLE: 221 cmd.type = SYSTEM_IO_CAPABLE; 222 perf = per_cpu(acfreq_data, cpumask_first(mask))->acpi_data; 223 cmd.addr.io.port = perf->control_register.address; 224 cmd.addr.io.bit_width = perf->control_register.bit_width; 225 break; 226 default: 227 return 0; 228 } 229 230 cmd.mask = mask; 231 drv_read(&cmd); 232 233 pr_debug("get_cur_val = %u\n", cmd.val); 234 235 return cmd.val; 236 } 237 238 static unsigned int get_cur_freq_on_cpu(unsigned int cpu) 239 { 240 struct acpi_cpufreq_data *data = per_cpu(acfreq_data, cpu); 241 unsigned int freq; 242 unsigned int cached_freq; 243 244 pr_debug("get_cur_freq_on_cpu (%d)\n", cpu); 245 246 if (unlikely(data == NULL || 247 data->acpi_data == NULL || data->freq_table == NULL)) { 248 return 0; 249 } 250 251 cached_freq = data->freq_table[data->acpi_data->state].frequency; 252 freq = extract_freq(get_cur_val(cpumask_of(cpu)), data); 253 if (freq != cached_freq) { 254 /* 255 * The dreaded BIOS frequency change behind our back. 256 * Force set the frequency on next target call. 257 */ 258 data->resume = 1; 259 } 260 261 pr_debug("cur freq = %u\n", freq); 262 263 return freq; 264 } 265 266 static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq, 267 struct acpi_cpufreq_data *data) 268 { 269 unsigned int cur_freq; 270 unsigned int i; 271 272 for (i = 0; i < 100; i++) { 273 cur_freq = extract_freq(get_cur_val(mask), data); 274 if (cur_freq == freq) 275 return 1; 276 udelay(10); 277 } 278 return 0; 279 } 280 281 static int acpi_cpufreq_target(struct cpufreq_policy *policy, 282 unsigned int target_freq, unsigned int relation) 283 { 284 struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu); 285 struct acpi_processor_performance *perf; 286 struct cpufreq_freqs freqs; 287 struct drv_cmd cmd; 288 unsigned int next_state = 0; /* Index into freq_table */ 289 unsigned int next_perf_state = 0; /* Index into perf table */ 290 unsigned int i; 291 int result = 0; 292 293 pr_debug("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu); 294 295 if (unlikely(data == NULL || 296 data->acpi_data == NULL || data->freq_table == NULL)) { 297 return -ENODEV; 298 } 299 300 perf = data->acpi_data; 301 result = cpufreq_frequency_table_target(policy, 302 data->freq_table, 303 target_freq, 304 relation, &next_state); 305 if (unlikely(result)) { 306 result = -ENODEV; 307 goto out; 308 } 309 310 next_perf_state = data->freq_table[next_state].index; 311 if (perf->state == next_perf_state) { 312 if (unlikely(data->resume)) { 313 pr_debug("Called after resume, resetting to P%d\n", 314 next_perf_state); 315 data->resume = 0; 316 } else { 317 pr_debug("Already at target state (P%d)\n", 318 next_perf_state); 319 goto out; 320 } 321 } 322 323 switch (data->cpu_feature) { 324 case SYSTEM_INTEL_MSR_CAPABLE: 325 cmd.type = SYSTEM_INTEL_MSR_CAPABLE; 326 cmd.addr.msr.reg = MSR_IA32_PERF_CTL; 327 cmd.val = (u32) perf->states[next_perf_state].control; 328 break; 329 case SYSTEM_IO_CAPABLE: 330 cmd.type = SYSTEM_IO_CAPABLE; 331 cmd.addr.io.port = perf->control_register.address; 332 cmd.addr.io.bit_width = perf->control_register.bit_width; 333 cmd.val = (u32) perf->states[next_perf_state].control; 334 break; 335 default: 336 result = -ENODEV; 337 goto out; 338 } 339 340 /* cpufreq holds the hotplug lock, so we are safe from here on */ 341 if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY) 342 cmd.mask = policy->cpus; 343 else 344 cmd.mask = cpumask_of(policy->cpu); 345 346 freqs.old = perf->states[perf->state].core_frequency * 1000; 347 freqs.new = data->freq_table[next_state].frequency; 348 for_each_cpu(i, policy->cpus) { 349 freqs.cpu = i; 350 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); 351 } 352 353 drv_write(&cmd); 354 355 if (acpi_pstate_strict) { 356 if (!check_freqs(cmd.mask, freqs.new, data)) { 357 pr_debug("acpi_cpufreq_target failed (%d)\n", 358 policy->cpu); 359 result = -EAGAIN; 360 goto out; 361 } 362 } 363 364 for_each_cpu(i, policy->cpus) { 365 freqs.cpu = i; 366 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); 367 } 368 perf->state = next_perf_state; 369 370 out: 371 return result; 372 } 373 374 static int acpi_cpufreq_verify(struct cpufreq_policy *policy) 375 { 376 struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu); 377 378 pr_debug("acpi_cpufreq_verify\n"); 379 380 return cpufreq_frequency_table_verify(policy, data->freq_table); 381 } 382 383 static unsigned long 384 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu) 385 { 386 struct acpi_processor_performance *perf = data->acpi_data; 387 388 if (cpu_khz) { 389 /* search the closest match to cpu_khz */ 390 unsigned int i; 391 unsigned long freq; 392 unsigned long freqn = perf->states[0].core_frequency * 1000; 393 394 for (i = 0; i < (perf->state_count-1); i++) { 395 freq = freqn; 396 freqn = perf->states[i+1].core_frequency * 1000; 397 if ((2 * cpu_khz) > (freqn + freq)) { 398 perf->state = i; 399 return freq; 400 } 401 } 402 perf->state = perf->state_count-1; 403 return freqn; 404 } else { 405 /* assume CPU is at P0... */ 406 perf->state = 0; 407 return perf->states[0].core_frequency * 1000; 408 } 409 } 410 411 static void free_acpi_perf_data(void) 412 { 413 unsigned int i; 414 415 /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */ 416 for_each_possible_cpu(i) 417 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i) 418 ->shared_cpu_map); 419 free_percpu(acpi_perf_data); 420 } 421 422 /* 423 * acpi_cpufreq_early_init - initialize ACPI P-States library 424 * 425 * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c) 426 * in order to determine correct frequency and voltage pairings. We can 427 * do _PDC and _PSD and find out the processor dependency for the 428 * actual init that will happen later... 429 */ 430 static int __init acpi_cpufreq_early_init(void) 431 { 432 unsigned int i; 433 pr_debug("acpi_cpufreq_early_init\n"); 434 435 acpi_perf_data = alloc_percpu(struct acpi_processor_performance); 436 if (!acpi_perf_data) { 437 pr_debug("Memory allocation error for acpi_perf_data.\n"); 438 return -ENOMEM; 439 } 440 for_each_possible_cpu(i) { 441 if (!zalloc_cpumask_var_node( 442 &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map, 443 GFP_KERNEL, cpu_to_node(i))) { 444 445 /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */ 446 free_acpi_perf_data(); 447 return -ENOMEM; 448 } 449 } 450 451 /* Do initialization in ACPI core */ 452 acpi_processor_preregister_performance(acpi_perf_data); 453 return 0; 454 } 455 456 #ifdef CONFIG_SMP 457 /* 458 * Some BIOSes do SW_ANY coordination internally, either set it up in hw 459 * or do it in BIOS firmware and won't inform about it to OS. If not 460 * detected, this has a side effect of making CPU run at a different speed 461 * than OS intended it to run at. Detect it and handle it cleanly. 462 */ 463 static int bios_with_sw_any_bug; 464 465 static int sw_any_bug_found(const struct dmi_system_id *d) 466 { 467 bios_with_sw_any_bug = 1; 468 return 0; 469 } 470 471 static const struct dmi_system_id sw_any_bug_dmi_table[] = { 472 { 473 .callback = sw_any_bug_found, 474 .ident = "Supermicro Server X6DLP", 475 .matches = { 476 DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"), 477 DMI_MATCH(DMI_BIOS_VERSION, "080010"), 478 DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"), 479 }, 480 }, 481 { } 482 }; 483 484 static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c) 485 { 486 /* Intel Xeon Processor 7100 Series Specification Update 487 * http://www.intel.com/Assets/PDF/specupdate/314554.pdf 488 * AL30: A Machine Check Exception (MCE) Occurring during an 489 * Enhanced Intel SpeedStep Technology Ratio Change May Cause 490 * Both Processor Cores to Lock Up. */ 491 if (c->x86_vendor == X86_VENDOR_INTEL) { 492 if ((c->x86 == 15) && 493 (c->x86_model == 6) && 494 (c->x86_mask == 8)) { 495 printk(KERN_INFO "acpi-cpufreq: Intel(R) " 496 "Xeon(R) 7100 Errata AL30, processors may " 497 "lock up on frequency changes: disabling " 498 "acpi-cpufreq.\n"); 499 return -ENODEV; 500 } 501 } 502 return 0; 503 } 504 #endif 505 506 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy) 507 { 508 unsigned int i; 509 unsigned int valid_states = 0; 510 unsigned int cpu = policy->cpu; 511 struct acpi_cpufreq_data *data; 512 unsigned int result = 0; 513 struct cpuinfo_x86 *c = &cpu_data(policy->cpu); 514 struct acpi_processor_performance *perf; 515 #ifdef CONFIG_SMP 516 static int blacklisted; 517 #endif 518 519 pr_debug("acpi_cpufreq_cpu_init\n"); 520 521 #ifdef CONFIG_SMP 522 if (blacklisted) 523 return blacklisted; 524 blacklisted = acpi_cpufreq_blacklist(c); 525 if (blacklisted) 526 return blacklisted; 527 #endif 528 529 data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL); 530 if (!data) 531 return -ENOMEM; 532 533 data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu); 534 per_cpu(acfreq_data, cpu) = data; 535 536 if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) 537 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS; 538 539 result = acpi_processor_register_performance(data->acpi_data, cpu); 540 if (result) 541 goto err_free; 542 543 perf = data->acpi_data; 544 policy->shared_type = perf->shared_type; 545 546 /* 547 * Will let policy->cpus know about dependency only when software 548 * coordination is required. 549 */ 550 if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL || 551 policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) { 552 cpumask_copy(policy->cpus, perf->shared_cpu_map); 553 } 554 cpumask_copy(policy->related_cpus, perf->shared_cpu_map); 555 556 #ifdef CONFIG_SMP 557 dmi_check_system(sw_any_bug_dmi_table); 558 if (bios_with_sw_any_bug && cpumask_weight(policy->cpus) == 1) { 559 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL; 560 cpumask_copy(policy->cpus, cpu_core_mask(cpu)); 561 } 562 #endif 563 564 /* capability check */ 565 if (perf->state_count <= 1) { 566 pr_debug("No P-States\n"); 567 result = -ENODEV; 568 goto err_unreg; 569 } 570 571 if (perf->control_register.space_id != perf->status_register.space_id) { 572 result = -ENODEV; 573 goto err_unreg; 574 } 575 576 switch (perf->control_register.space_id) { 577 case ACPI_ADR_SPACE_SYSTEM_IO: 578 pr_debug("SYSTEM IO addr space\n"); 579 data->cpu_feature = SYSTEM_IO_CAPABLE; 580 break; 581 case ACPI_ADR_SPACE_FIXED_HARDWARE: 582 pr_debug("HARDWARE addr space\n"); 583 if (!check_est_cpu(cpu)) { 584 result = -ENODEV; 585 goto err_unreg; 586 } 587 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE; 588 break; 589 default: 590 pr_debug("Unknown addr space %d\n", 591 (u32) (perf->control_register.space_id)); 592 result = -ENODEV; 593 goto err_unreg; 594 } 595 596 data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * 597 (perf->state_count+1), GFP_KERNEL); 598 if (!data->freq_table) { 599 result = -ENOMEM; 600 goto err_unreg; 601 } 602 603 /* detect transition latency */ 604 policy->cpuinfo.transition_latency = 0; 605 for (i = 0; i < perf->state_count; i++) { 606 if ((perf->states[i].transition_latency * 1000) > 607 policy->cpuinfo.transition_latency) 608 policy->cpuinfo.transition_latency = 609 perf->states[i].transition_latency * 1000; 610 } 611 612 /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */ 613 if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE && 614 policy->cpuinfo.transition_latency > 20 * 1000) { 615 policy->cpuinfo.transition_latency = 20 * 1000; 616 printk_once(KERN_INFO 617 "P-state transition latency capped at 20 uS\n"); 618 } 619 620 /* table init */ 621 for (i = 0; i < perf->state_count; i++) { 622 if (i > 0 && perf->states[i].core_frequency >= 623 data->freq_table[valid_states-1].frequency / 1000) 624 continue; 625 626 data->freq_table[valid_states].index = i; 627 data->freq_table[valid_states].frequency = 628 perf->states[i].core_frequency * 1000; 629 valid_states++; 630 } 631 data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END; 632 perf->state = 0; 633 634 result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table); 635 if (result) 636 goto err_freqfree; 637 638 if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq) 639 printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n"); 640 641 switch (perf->control_register.space_id) { 642 case ACPI_ADR_SPACE_SYSTEM_IO: 643 /* Current speed is unknown and not detectable by IO port */ 644 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu); 645 break; 646 case ACPI_ADR_SPACE_FIXED_HARDWARE: 647 acpi_cpufreq_driver.get = get_cur_freq_on_cpu; 648 policy->cur = get_cur_freq_on_cpu(cpu); 649 break; 650 default: 651 break; 652 } 653 654 /* notify BIOS that we exist */ 655 acpi_processor_notify_smm(THIS_MODULE); 656 657 /* Check for APERF/MPERF support in hardware */ 658 if (boot_cpu_has(X86_FEATURE_APERFMPERF)) 659 acpi_cpufreq_driver.getavg = cpufreq_get_measured_perf; 660 661 pr_debug("CPU%u - ACPI performance management activated.\n", cpu); 662 for (i = 0; i < perf->state_count; i++) 663 pr_debug(" %cP%d: %d MHz, %d mW, %d uS\n", 664 (i == perf->state ? '*' : ' '), i, 665 (u32) perf->states[i].core_frequency, 666 (u32) perf->states[i].power, 667 (u32) perf->states[i].transition_latency); 668 669 cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu); 670 671 /* 672 * the first call to ->target() should result in us actually 673 * writing something to the appropriate registers. 674 */ 675 data->resume = 1; 676 677 return result; 678 679 err_freqfree: 680 kfree(data->freq_table); 681 err_unreg: 682 acpi_processor_unregister_performance(perf, cpu); 683 err_free: 684 kfree(data); 685 per_cpu(acfreq_data, cpu) = NULL; 686 687 return result; 688 } 689 690 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy) 691 { 692 struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu); 693 694 pr_debug("acpi_cpufreq_cpu_exit\n"); 695 696 if (data) { 697 cpufreq_frequency_table_put_attr(policy->cpu); 698 per_cpu(acfreq_data, policy->cpu) = NULL; 699 acpi_processor_unregister_performance(data->acpi_data, 700 policy->cpu); 701 kfree(data->freq_table); 702 kfree(data); 703 } 704 705 return 0; 706 } 707 708 static int acpi_cpufreq_resume(struct cpufreq_policy *policy) 709 { 710 struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu); 711 712 pr_debug("acpi_cpufreq_resume\n"); 713 714 data->resume = 1; 715 716 return 0; 717 } 718 719 static struct freq_attr *acpi_cpufreq_attr[] = { 720 &cpufreq_freq_attr_scaling_available_freqs, 721 NULL, 722 }; 723 724 static struct cpufreq_driver acpi_cpufreq_driver = { 725 .verify = acpi_cpufreq_verify, 726 .target = acpi_cpufreq_target, 727 .bios_limit = acpi_processor_get_bios_limit, 728 .init = acpi_cpufreq_cpu_init, 729 .exit = acpi_cpufreq_cpu_exit, 730 .resume = acpi_cpufreq_resume, 731 .name = "acpi-cpufreq", 732 .owner = THIS_MODULE, 733 .attr = acpi_cpufreq_attr, 734 }; 735 736 static int __init acpi_cpufreq_init(void) 737 { 738 int ret; 739 740 if (acpi_disabled) 741 return 0; 742 743 pr_debug("acpi_cpufreq_init\n"); 744 745 ret = acpi_cpufreq_early_init(); 746 if (ret) 747 return ret; 748 749 ret = cpufreq_register_driver(&acpi_cpufreq_driver); 750 if (ret) 751 free_acpi_perf_data(); 752 753 return ret; 754 } 755 756 static void __exit acpi_cpufreq_exit(void) 757 { 758 pr_debug("acpi_cpufreq_exit\n"); 759 760 cpufreq_unregister_driver(&acpi_cpufreq_driver); 761 762 free_acpi_perf_data(); 763 } 764 765 module_param(acpi_pstate_strict, uint, 0644); 766 MODULE_PARM_DESC(acpi_pstate_strict, 767 "value 0 or non-zero. non-zero -> strict ACPI checks are " 768 "performed during frequency changes."); 769 770 late_initcall(acpi_cpufreq_init); 771 module_exit(acpi_cpufreq_exit); 772 773 MODULE_ALIAS("acpi"); 774