1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * amd-pstate.c - AMD Processor P-state Frequency Driver 4 * 5 * Copyright (C) 2021 Advanced Micro Devices, Inc. All Rights Reserved. 6 * 7 * Author: Huang Rui <ray.huang@amd.com> 8 * 9 * AMD P-State introduces a new CPU performance scaling design for AMD 10 * processors using the ACPI Collaborative Performance and Power Control (CPPC) 11 * feature which works with the AMD SMU firmware providing a finer grained 12 * frequency control range. It is to replace the legacy ACPI P-States control, 13 * allows a flexible, low-latency interface for the Linux kernel to directly 14 * communicate the performance hints to hardware. 15 * 16 * AMD P-State is supported on recent AMD Zen base CPU series include some of 17 * Zen2 and Zen3 processors. _CPC needs to be present in the ACPI tables of AMD 18 * P-State supported system. And there are two types of hardware implementations 19 * for AMD P-State: 1) Full MSR Solution and 2) Shared Memory Solution. 20 * X86_FEATURE_CPPC CPU feature flag is used to distinguish the different types. 21 */ 22 23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 24 25 #include <linux/kernel.h> 26 #include <linux/module.h> 27 #include <linux/init.h> 28 #include <linux/smp.h> 29 #include <linux/sched.h> 30 #include <linux/cpufreq.h> 31 #include <linux/compiler.h> 32 #include <linux/dmi.h> 33 #include <linux/slab.h> 34 #include <linux/acpi.h> 35 #include <linux/io.h> 36 #include <linux/delay.h> 37 #include <linux/uaccess.h> 38 #include <linux/static_call.h> 39 #include <linux/amd-pstate.h> 40 41 #include <acpi/processor.h> 42 #include <acpi/cppc_acpi.h> 43 44 #include <asm/msr.h> 45 #include <asm/processor.h> 46 #include <asm/cpufeature.h> 47 #include <asm/cpu_device_id.h> 48 #include "amd-pstate-trace.h" 49 50 #define AMD_PSTATE_TRANSITION_LATENCY 20000 51 #define AMD_PSTATE_TRANSITION_DELAY 1000 52 53 /* 54 * TODO: We need more time to fine tune processors with shared memory solution 55 * with community together. 56 * 57 * There are some performance drops on the CPU benchmarks which reports from 58 * Suse. We are co-working with them to fine tune the shared memory solution. So 59 * we disable it by default to go acpi-cpufreq on these processors and add a 60 * module parameter to be able to enable it manually for debugging. 61 */ 62 static struct cpufreq_driver *current_pstate_driver; 63 static struct cpufreq_driver amd_pstate_driver; 64 static struct cpufreq_driver amd_pstate_epp_driver; 65 static int cppc_state = AMD_PSTATE_DISABLE; 66 struct kobject *amd_pstate_kobj; 67 68 /* 69 * AMD Energy Preference Performance (EPP) 70 * The EPP is used in the CCLK DPM controller to drive 71 * the frequency that a core is going to operate during 72 * short periods of activity. EPP values will be utilized for 73 * different OS profiles (balanced, performance, power savings) 74 * display strings corresponding to EPP index in the 75 * energy_perf_strings[] 76 * index String 77 *------------------------------------- 78 * 0 default 79 * 1 performance 80 * 2 balance_performance 81 * 3 balance_power 82 * 4 power 83 */ 84 enum energy_perf_value_index { 85 EPP_INDEX_DEFAULT = 0, 86 EPP_INDEX_PERFORMANCE, 87 EPP_INDEX_BALANCE_PERFORMANCE, 88 EPP_INDEX_BALANCE_POWERSAVE, 89 EPP_INDEX_POWERSAVE, 90 }; 91 92 static const char * const energy_perf_strings[] = { 93 [EPP_INDEX_DEFAULT] = "default", 94 [EPP_INDEX_PERFORMANCE] = "performance", 95 [EPP_INDEX_BALANCE_PERFORMANCE] = "balance_performance", 96 [EPP_INDEX_BALANCE_POWERSAVE] = "balance_power", 97 [EPP_INDEX_POWERSAVE] = "power", 98 NULL 99 }; 100 101 static unsigned int epp_values[] = { 102 [EPP_INDEX_DEFAULT] = 0, 103 [EPP_INDEX_PERFORMANCE] = AMD_CPPC_EPP_PERFORMANCE, 104 [EPP_INDEX_BALANCE_PERFORMANCE] = AMD_CPPC_EPP_BALANCE_PERFORMANCE, 105 [EPP_INDEX_BALANCE_POWERSAVE] = AMD_CPPC_EPP_BALANCE_POWERSAVE, 106 [EPP_INDEX_POWERSAVE] = AMD_CPPC_EPP_POWERSAVE, 107 }; 108 109 static inline int get_mode_idx_from_str(const char *str, size_t size) 110 { 111 int i; 112 113 for (i=0; i < AMD_PSTATE_MAX; i++) { 114 if (!strncmp(str, amd_pstate_mode_string[i], size)) 115 return i; 116 } 117 return -EINVAL; 118 } 119 120 static DEFINE_MUTEX(amd_pstate_limits_lock); 121 static DEFINE_MUTEX(amd_pstate_driver_lock); 122 123 static s16 amd_pstate_get_epp(struct amd_cpudata *cpudata, u64 cppc_req_cached) 124 { 125 u64 epp; 126 int ret; 127 128 if (boot_cpu_has(X86_FEATURE_CPPC)) { 129 if (!cppc_req_cached) { 130 epp = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, 131 &cppc_req_cached); 132 if (epp) 133 return epp; 134 } 135 epp = (cppc_req_cached >> 24) & 0xFF; 136 } else { 137 ret = cppc_get_epp_perf(cpudata->cpu, &epp); 138 if (ret < 0) { 139 pr_debug("Could not retrieve energy perf value (%d)\n", ret); 140 return -EIO; 141 } 142 } 143 144 return (s16)(epp & 0xff); 145 } 146 147 static int amd_pstate_get_energy_pref_index(struct amd_cpudata *cpudata) 148 { 149 s16 epp; 150 int index = -EINVAL; 151 152 epp = amd_pstate_get_epp(cpudata, 0); 153 if (epp < 0) 154 return epp; 155 156 switch (epp) { 157 case AMD_CPPC_EPP_PERFORMANCE: 158 index = EPP_INDEX_PERFORMANCE; 159 break; 160 case AMD_CPPC_EPP_BALANCE_PERFORMANCE: 161 index = EPP_INDEX_BALANCE_PERFORMANCE; 162 break; 163 case AMD_CPPC_EPP_BALANCE_POWERSAVE: 164 index = EPP_INDEX_BALANCE_POWERSAVE; 165 break; 166 case AMD_CPPC_EPP_POWERSAVE: 167 index = EPP_INDEX_POWERSAVE; 168 break; 169 default: 170 break; 171 } 172 173 return index; 174 } 175 176 static int amd_pstate_set_epp(struct amd_cpudata *cpudata, u32 epp) 177 { 178 int ret; 179 struct cppc_perf_ctrls perf_ctrls; 180 181 if (boot_cpu_has(X86_FEATURE_CPPC)) { 182 u64 value = READ_ONCE(cpudata->cppc_req_cached); 183 184 value &= ~GENMASK_ULL(31, 24); 185 value |= (u64)epp << 24; 186 WRITE_ONCE(cpudata->cppc_req_cached, value); 187 188 ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value); 189 if (!ret) 190 cpudata->epp_cached = epp; 191 } else { 192 perf_ctrls.energy_perf = epp; 193 ret = cppc_set_epp_perf(cpudata->cpu, &perf_ctrls, 1); 194 if (ret) { 195 pr_debug("failed to set energy perf value (%d)\n", ret); 196 return ret; 197 } 198 cpudata->epp_cached = epp; 199 } 200 201 return ret; 202 } 203 204 static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata, 205 int pref_index) 206 { 207 int epp = -EINVAL; 208 int ret; 209 210 if (!pref_index) { 211 pr_debug("EPP pref_index is invalid\n"); 212 return -EINVAL; 213 } 214 215 if (epp == -EINVAL) 216 epp = epp_values[pref_index]; 217 218 if (epp > 0 && cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) { 219 pr_debug("EPP cannot be set under performance policy\n"); 220 return -EBUSY; 221 } 222 223 ret = amd_pstate_set_epp(cpudata, epp); 224 225 return ret; 226 } 227 228 static inline int pstate_enable(bool enable) 229 { 230 return wrmsrl_safe(MSR_AMD_CPPC_ENABLE, enable); 231 } 232 233 static int cppc_enable(bool enable) 234 { 235 int cpu, ret = 0; 236 struct cppc_perf_ctrls perf_ctrls; 237 238 for_each_present_cpu(cpu) { 239 ret = cppc_set_enable(cpu, enable); 240 if (ret) 241 return ret; 242 243 /* Enable autonomous mode for EPP */ 244 if (cppc_state == AMD_PSTATE_ACTIVE) { 245 /* Set desired perf as zero to allow EPP firmware control */ 246 perf_ctrls.desired_perf = 0; 247 ret = cppc_set_perf(cpu, &perf_ctrls); 248 if (ret) 249 return ret; 250 } 251 } 252 253 return ret; 254 } 255 256 DEFINE_STATIC_CALL(amd_pstate_enable, pstate_enable); 257 258 static inline int amd_pstate_enable(bool enable) 259 { 260 return static_call(amd_pstate_enable)(enable); 261 } 262 263 static int pstate_init_perf(struct amd_cpudata *cpudata) 264 { 265 u64 cap1; 266 u32 highest_perf; 267 268 int ret = rdmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1, 269 &cap1); 270 if (ret) 271 return ret; 272 273 /* 274 * TODO: Introduce AMD specific power feature. 275 * 276 * CPPC entry doesn't indicate the highest performance in some ASICs. 277 */ 278 highest_perf = amd_get_highest_perf(); 279 if (highest_perf > AMD_CPPC_HIGHEST_PERF(cap1)) 280 highest_perf = AMD_CPPC_HIGHEST_PERF(cap1); 281 282 WRITE_ONCE(cpudata->highest_perf, highest_perf); 283 284 WRITE_ONCE(cpudata->nominal_perf, AMD_CPPC_NOMINAL_PERF(cap1)); 285 WRITE_ONCE(cpudata->lowest_nonlinear_perf, AMD_CPPC_LOWNONLIN_PERF(cap1)); 286 WRITE_ONCE(cpudata->lowest_perf, AMD_CPPC_LOWEST_PERF(cap1)); 287 288 return 0; 289 } 290 291 static int cppc_init_perf(struct amd_cpudata *cpudata) 292 { 293 struct cppc_perf_caps cppc_perf; 294 u32 highest_perf; 295 296 int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); 297 if (ret) 298 return ret; 299 300 highest_perf = amd_get_highest_perf(); 301 if (highest_perf > cppc_perf.highest_perf) 302 highest_perf = cppc_perf.highest_perf; 303 304 WRITE_ONCE(cpudata->highest_perf, highest_perf); 305 306 WRITE_ONCE(cpudata->nominal_perf, cppc_perf.nominal_perf); 307 WRITE_ONCE(cpudata->lowest_nonlinear_perf, 308 cppc_perf.lowest_nonlinear_perf); 309 WRITE_ONCE(cpudata->lowest_perf, cppc_perf.lowest_perf); 310 311 return 0; 312 } 313 314 DEFINE_STATIC_CALL(amd_pstate_init_perf, pstate_init_perf); 315 316 static inline int amd_pstate_init_perf(struct amd_cpudata *cpudata) 317 { 318 return static_call(amd_pstate_init_perf)(cpudata); 319 } 320 321 static void pstate_update_perf(struct amd_cpudata *cpudata, u32 min_perf, 322 u32 des_perf, u32 max_perf, bool fast_switch) 323 { 324 if (fast_switch) 325 wrmsrl(MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached)); 326 else 327 wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, 328 READ_ONCE(cpudata->cppc_req_cached)); 329 } 330 331 static void cppc_update_perf(struct amd_cpudata *cpudata, 332 u32 min_perf, u32 des_perf, 333 u32 max_perf, bool fast_switch) 334 { 335 struct cppc_perf_ctrls perf_ctrls; 336 337 perf_ctrls.max_perf = max_perf; 338 perf_ctrls.min_perf = min_perf; 339 perf_ctrls.desired_perf = des_perf; 340 341 cppc_set_perf(cpudata->cpu, &perf_ctrls); 342 } 343 344 DEFINE_STATIC_CALL(amd_pstate_update_perf, pstate_update_perf); 345 346 static inline void amd_pstate_update_perf(struct amd_cpudata *cpudata, 347 u32 min_perf, u32 des_perf, 348 u32 max_perf, bool fast_switch) 349 { 350 static_call(amd_pstate_update_perf)(cpudata, min_perf, des_perf, 351 max_perf, fast_switch); 352 } 353 354 static inline bool amd_pstate_sample(struct amd_cpudata *cpudata) 355 { 356 u64 aperf, mperf, tsc; 357 unsigned long flags; 358 359 local_irq_save(flags); 360 rdmsrl(MSR_IA32_APERF, aperf); 361 rdmsrl(MSR_IA32_MPERF, mperf); 362 tsc = rdtsc(); 363 364 if (cpudata->prev.mperf == mperf || cpudata->prev.tsc == tsc) { 365 local_irq_restore(flags); 366 return false; 367 } 368 369 local_irq_restore(flags); 370 371 cpudata->cur.aperf = aperf; 372 cpudata->cur.mperf = mperf; 373 cpudata->cur.tsc = tsc; 374 cpudata->cur.aperf -= cpudata->prev.aperf; 375 cpudata->cur.mperf -= cpudata->prev.mperf; 376 cpudata->cur.tsc -= cpudata->prev.tsc; 377 378 cpudata->prev.aperf = aperf; 379 cpudata->prev.mperf = mperf; 380 cpudata->prev.tsc = tsc; 381 382 cpudata->freq = div64_u64((cpudata->cur.aperf * cpu_khz), cpudata->cur.mperf); 383 384 return true; 385 } 386 387 static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf, 388 u32 des_perf, u32 max_perf, bool fast_switch) 389 { 390 u64 prev = READ_ONCE(cpudata->cppc_req_cached); 391 u64 value = prev; 392 393 des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf); 394 value &= ~AMD_CPPC_MIN_PERF(~0L); 395 value |= AMD_CPPC_MIN_PERF(min_perf); 396 397 value &= ~AMD_CPPC_DES_PERF(~0L); 398 value |= AMD_CPPC_DES_PERF(des_perf); 399 400 value &= ~AMD_CPPC_MAX_PERF(~0L); 401 value |= AMD_CPPC_MAX_PERF(max_perf); 402 403 if (trace_amd_pstate_perf_enabled() && amd_pstate_sample(cpudata)) { 404 trace_amd_pstate_perf(min_perf, des_perf, max_perf, cpudata->freq, 405 cpudata->cur.mperf, cpudata->cur.aperf, cpudata->cur.tsc, 406 cpudata->cpu, (value != prev), fast_switch); 407 } 408 409 if (value == prev) 410 return; 411 412 WRITE_ONCE(cpudata->cppc_req_cached, value); 413 414 amd_pstate_update_perf(cpudata, min_perf, des_perf, 415 max_perf, fast_switch); 416 } 417 418 static int amd_pstate_verify(struct cpufreq_policy_data *policy) 419 { 420 cpufreq_verify_within_cpu_limits(policy); 421 422 return 0; 423 } 424 425 static int amd_pstate_target(struct cpufreq_policy *policy, 426 unsigned int target_freq, 427 unsigned int relation) 428 { 429 struct cpufreq_freqs freqs; 430 struct amd_cpudata *cpudata = policy->driver_data; 431 unsigned long max_perf, min_perf, des_perf, cap_perf; 432 433 if (!cpudata->max_freq) 434 return -ENODEV; 435 436 cap_perf = READ_ONCE(cpudata->highest_perf); 437 min_perf = READ_ONCE(cpudata->lowest_perf); 438 max_perf = cap_perf; 439 440 freqs.old = policy->cur; 441 freqs.new = target_freq; 442 443 des_perf = DIV_ROUND_CLOSEST(target_freq * cap_perf, 444 cpudata->max_freq); 445 446 cpufreq_freq_transition_begin(policy, &freqs); 447 amd_pstate_update(cpudata, min_perf, des_perf, 448 max_perf, false); 449 cpufreq_freq_transition_end(policy, &freqs, false); 450 451 return 0; 452 } 453 454 static void amd_pstate_adjust_perf(unsigned int cpu, 455 unsigned long _min_perf, 456 unsigned long target_perf, 457 unsigned long capacity) 458 { 459 unsigned long max_perf, min_perf, des_perf, 460 cap_perf, lowest_nonlinear_perf; 461 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); 462 struct amd_cpudata *cpudata = policy->driver_data; 463 464 cap_perf = READ_ONCE(cpudata->highest_perf); 465 lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf); 466 467 des_perf = cap_perf; 468 if (target_perf < capacity) 469 des_perf = DIV_ROUND_UP(cap_perf * target_perf, capacity); 470 471 min_perf = READ_ONCE(cpudata->highest_perf); 472 if (_min_perf < capacity) 473 min_perf = DIV_ROUND_UP(cap_perf * _min_perf, capacity); 474 475 if (min_perf < lowest_nonlinear_perf) 476 min_perf = lowest_nonlinear_perf; 477 478 max_perf = cap_perf; 479 if (max_perf < min_perf) 480 max_perf = min_perf; 481 482 amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true); 483 cpufreq_cpu_put(policy); 484 } 485 486 static int amd_get_min_freq(struct amd_cpudata *cpudata) 487 { 488 struct cppc_perf_caps cppc_perf; 489 490 int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); 491 if (ret) 492 return ret; 493 494 /* Switch to khz */ 495 return cppc_perf.lowest_freq * 1000; 496 } 497 498 static int amd_get_max_freq(struct amd_cpudata *cpudata) 499 { 500 struct cppc_perf_caps cppc_perf; 501 u32 max_perf, max_freq, nominal_freq, nominal_perf; 502 u64 boost_ratio; 503 504 int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); 505 if (ret) 506 return ret; 507 508 nominal_freq = cppc_perf.nominal_freq; 509 nominal_perf = READ_ONCE(cpudata->nominal_perf); 510 max_perf = READ_ONCE(cpudata->highest_perf); 511 512 boost_ratio = div_u64(max_perf << SCHED_CAPACITY_SHIFT, 513 nominal_perf); 514 515 max_freq = nominal_freq * boost_ratio >> SCHED_CAPACITY_SHIFT; 516 517 /* Switch to khz */ 518 return max_freq * 1000; 519 } 520 521 static int amd_get_nominal_freq(struct amd_cpudata *cpudata) 522 { 523 struct cppc_perf_caps cppc_perf; 524 525 int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); 526 if (ret) 527 return ret; 528 529 /* Switch to khz */ 530 return cppc_perf.nominal_freq * 1000; 531 } 532 533 static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata) 534 { 535 struct cppc_perf_caps cppc_perf; 536 u32 lowest_nonlinear_freq, lowest_nonlinear_perf, 537 nominal_freq, nominal_perf; 538 u64 lowest_nonlinear_ratio; 539 540 int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); 541 if (ret) 542 return ret; 543 544 nominal_freq = cppc_perf.nominal_freq; 545 nominal_perf = READ_ONCE(cpudata->nominal_perf); 546 547 lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf; 548 549 lowest_nonlinear_ratio = div_u64(lowest_nonlinear_perf << SCHED_CAPACITY_SHIFT, 550 nominal_perf); 551 552 lowest_nonlinear_freq = nominal_freq * lowest_nonlinear_ratio >> SCHED_CAPACITY_SHIFT; 553 554 /* Switch to khz */ 555 return lowest_nonlinear_freq * 1000; 556 } 557 558 static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state) 559 { 560 struct amd_cpudata *cpudata = policy->driver_data; 561 int ret; 562 563 if (!cpudata->boost_supported) { 564 pr_err("Boost mode is not supported by this processor or SBIOS\n"); 565 return -EINVAL; 566 } 567 568 if (state) 569 policy->cpuinfo.max_freq = cpudata->max_freq; 570 else 571 policy->cpuinfo.max_freq = cpudata->nominal_freq; 572 573 policy->max = policy->cpuinfo.max_freq; 574 575 ret = freq_qos_update_request(&cpudata->req[1], 576 policy->cpuinfo.max_freq); 577 if (ret < 0) 578 return ret; 579 580 return 0; 581 } 582 583 static void amd_pstate_boost_init(struct amd_cpudata *cpudata) 584 { 585 u32 highest_perf, nominal_perf; 586 587 highest_perf = READ_ONCE(cpudata->highest_perf); 588 nominal_perf = READ_ONCE(cpudata->nominal_perf); 589 590 if (highest_perf <= nominal_perf) 591 return; 592 593 cpudata->boost_supported = true; 594 current_pstate_driver->boost_enabled = true; 595 } 596 597 static void amd_perf_ctl_reset(unsigned int cpu) 598 { 599 wrmsrl_on_cpu(cpu, MSR_AMD_PERF_CTL, 0); 600 } 601 602 static int amd_pstate_cpu_init(struct cpufreq_policy *policy) 603 { 604 int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret; 605 struct device *dev; 606 struct amd_cpudata *cpudata; 607 608 /* 609 * Resetting PERF_CTL_MSR will put the CPU in P0 frequency, 610 * which is ideal for initialization process. 611 */ 612 amd_perf_ctl_reset(policy->cpu); 613 dev = get_cpu_device(policy->cpu); 614 if (!dev) 615 return -ENODEV; 616 617 cpudata = kzalloc(sizeof(*cpudata), GFP_KERNEL); 618 if (!cpudata) 619 return -ENOMEM; 620 621 cpudata->cpu = policy->cpu; 622 623 ret = amd_pstate_init_perf(cpudata); 624 if (ret) 625 goto free_cpudata1; 626 627 min_freq = amd_get_min_freq(cpudata); 628 max_freq = amd_get_max_freq(cpudata); 629 nominal_freq = amd_get_nominal_freq(cpudata); 630 lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata); 631 632 if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) { 633 dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n", 634 min_freq, max_freq); 635 ret = -EINVAL; 636 goto free_cpudata1; 637 } 638 639 policy->cpuinfo.transition_latency = AMD_PSTATE_TRANSITION_LATENCY; 640 policy->transition_delay_us = AMD_PSTATE_TRANSITION_DELAY; 641 642 policy->min = min_freq; 643 policy->max = max_freq; 644 645 policy->cpuinfo.min_freq = min_freq; 646 policy->cpuinfo.max_freq = max_freq; 647 648 /* It will be updated by governor */ 649 policy->cur = policy->cpuinfo.min_freq; 650 651 if (boot_cpu_has(X86_FEATURE_CPPC)) 652 policy->fast_switch_possible = true; 653 654 ret = freq_qos_add_request(&policy->constraints, &cpudata->req[0], 655 FREQ_QOS_MIN, policy->cpuinfo.min_freq); 656 if (ret < 0) { 657 dev_err(dev, "Failed to add min-freq constraint (%d)\n", ret); 658 goto free_cpudata1; 659 } 660 661 ret = freq_qos_add_request(&policy->constraints, &cpudata->req[1], 662 FREQ_QOS_MAX, policy->cpuinfo.max_freq); 663 if (ret < 0) { 664 dev_err(dev, "Failed to add max-freq constraint (%d)\n", ret); 665 goto free_cpudata2; 666 } 667 668 /* Initial processor data capability frequencies */ 669 cpudata->max_freq = max_freq; 670 cpudata->min_freq = min_freq; 671 cpudata->nominal_freq = nominal_freq; 672 cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq; 673 674 policy->driver_data = cpudata; 675 676 amd_pstate_boost_init(cpudata); 677 if (!current_pstate_driver->adjust_perf) 678 current_pstate_driver->adjust_perf = amd_pstate_adjust_perf; 679 680 return 0; 681 682 free_cpudata2: 683 freq_qos_remove_request(&cpudata->req[0]); 684 free_cpudata1: 685 kfree(cpudata); 686 return ret; 687 } 688 689 static int amd_pstate_cpu_exit(struct cpufreq_policy *policy) 690 { 691 struct amd_cpudata *cpudata = policy->driver_data; 692 693 freq_qos_remove_request(&cpudata->req[1]); 694 freq_qos_remove_request(&cpudata->req[0]); 695 kfree(cpudata); 696 697 return 0; 698 } 699 700 static int amd_pstate_cpu_resume(struct cpufreq_policy *policy) 701 { 702 int ret; 703 704 ret = amd_pstate_enable(true); 705 if (ret) 706 pr_err("failed to enable amd-pstate during resume, return %d\n", ret); 707 708 return ret; 709 } 710 711 static int amd_pstate_cpu_suspend(struct cpufreq_policy *policy) 712 { 713 int ret; 714 715 ret = amd_pstate_enable(false); 716 if (ret) 717 pr_err("failed to disable amd-pstate during suspend, return %d\n", ret); 718 719 return ret; 720 } 721 722 /* Sysfs attributes */ 723 724 /* 725 * This frequency is to indicate the maximum hardware frequency. 726 * If boost is not active but supported, the frequency will be larger than the 727 * one in cpuinfo. 728 */ 729 static ssize_t show_amd_pstate_max_freq(struct cpufreq_policy *policy, 730 char *buf) 731 { 732 int max_freq; 733 struct amd_cpudata *cpudata = policy->driver_data; 734 735 max_freq = amd_get_max_freq(cpudata); 736 if (max_freq < 0) 737 return max_freq; 738 739 return sysfs_emit(buf, "%u\n", max_freq); 740 } 741 742 static ssize_t show_amd_pstate_lowest_nonlinear_freq(struct cpufreq_policy *policy, 743 char *buf) 744 { 745 int freq; 746 struct amd_cpudata *cpudata = policy->driver_data; 747 748 freq = amd_get_lowest_nonlinear_freq(cpudata); 749 if (freq < 0) 750 return freq; 751 752 return sysfs_emit(buf, "%u\n", freq); 753 } 754 755 /* 756 * In some of ASICs, the highest_perf is not the one in the _CPC table, so we 757 * need to expose it to sysfs. 758 */ 759 static ssize_t show_amd_pstate_highest_perf(struct cpufreq_policy *policy, 760 char *buf) 761 { 762 u32 perf; 763 struct amd_cpudata *cpudata = policy->driver_data; 764 765 perf = READ_ONCE(cpudata->highest_perf); 766 767 return sysfs_emit(buf, "%u\n", perf); 768 } 769 770 static ssize_t show_energy_performance_available_preferences( 771 struct cpufreq_policy *policy, char *buf) 772 { 773 int i = 0; 774 int offset = 0; 775 776 while (energy_perf_strings[i] != NULL) 777 offset += sysfs_emit_at(buf, offset, "%s ", energy_perf_strings[i++]); 778 779 sysfs_emit_at(buf, offset, "\n"); 780 781 return offset; 782 } 783 784 static ssize_t store_energy_performance_preference( 785 struct cpufreq_policy *policy, const char *buf, size_t count) 786 { 787 struct amd_cpudata *cpudata = policy->driver_data; 788 char str_preference[21]; 789 ssize_t ret; 790 791 ret = sscanf(buf, "%20s", str_preference); 792 if (ret != 1) 793 return -EINVAL; 794 795 ret = match_string(energy_perf_strings, -1, str_preference); 796 if (ret < 0) 797 return -EINVAL; 798 799 mutex_lock(&amd_pstate_limits_lock); 800 ret = amd_pstate_set_energy_pref_index(cpudata, ret); 801 mutex_unlock(&amd_pstate_limits_lock); 802 803 return ret ?: count; 804 } 805 806 static ssize_t show_energy_performance_preference( 807 struct cpufreq_policy *policy, char *buf) 808 { 809 struct amd_cpudata *cpudata = policy->driver_data; 810 int preference; 811 812 preference = amd_pstate_get_energy_pref_index(cpudata); 813 if (preference < 0) 814 return preference; 815 816 return sysfs_emit(buf, "%s\n", energy_perf_strings[preference]); 817 } 818 819 static ssize_t amd_pstate_show_status(char *buf) 820 { 821 if (!current_pstate_driver) 822 return sysfs_emit(buf, "disable\n"); 823 824 return sysfs_emit(buf, "%s\n", amd_pstate_mode_string[cppc_state]); 825 } 826 827 static void amd_pstate_driver_cleanup(void) 828 { 829 current_pstate_driver = NULL; 830 } 831 832 static int amd_pstate_update_status(const char *buf, size_t size) 833 { 834 int ret = 0; 835 int mode_idx; 836 837 if (size > 7 || size < 6) 838 return -EINVAL; 839 mode_idx = get_mode_idx_from_str(buf, size); 840 841 switch(mode_idx) { 842 case AMD_PSTATE_DISABLE: 843 if (current_pstate_driver) { 844 cpufreq_unregister_driver(current_pstate_driver); 845 amd_pstate_driver_cleanup(); 846 } 847 break; 848 case AMD_PSTATE_PASSIVE: 849 if (current_pstate_driver) { 850 if (current_pstate_driver == &amd_pstate_driver) 851 return 0; 852 cpufreq_unregister_driver(current_pstate_driver); 853 } 854 855 current_pstate_driver = &amd_pstate_driver; 856 cppc_state = AMD_PSTATE_PASSIVE; 857 ret = cpufreq_register_driver(current_pstate_driver); 858 break; 859 case AMD_PSTATE_ACTIVE: 860 if (current_pstate_driver) { 861 if (current_pstate_driver == &amd_pstate_epp_driver) 862 return 0; 863 cpufreq_unregister_driver(current_pstate_driver); 864 } 865 866 current_pstate_driver = &amd_pstate_epp_driver; 867 cppc_state = AMD_PSTATE_ACTIVE; 868 ret = cpufreq_register_driver(current_pstate_driver); 869 break; 870 default: 871 ret = -EINVAL; 872 break; 873 } 874 875 return ret; 876 } 877 878 static ssize_t show_status(struct kobject *kobj, 879 struct kobj_attribute *attr, char *buf) 880 { 881 ssize_t ret; 882 883 mutex_lock(&amd_pstate_driver_lock); 884 ret = amd_pstate_show_status(buf); 885 mutex_unlock(&amd_pstate_driver_lock); 886 887 return ret; 888 } 889 890 static ssize_t store_status(struct kobject *a, struct kobj_attribute *b, 891 const char *buf, size_t count) 892 { 893 char *p = memchr(buf, '\n', count); 894 int ret; 895 896 mutex_lock(&amd_pstate_driver_lock); 897 ret = amd_pstate_update_status(buf, p ? p - buf : count); 898 mutex_unlock(&amd_pstate_driver_lock); 899 900 return ret < 0 ? ret : count; 901 } 902 903 cpufreq_freq_attr_ro(amd_pstate_max_freq); 904 cpufreq_freq_attr_ro(amd_pstate_lowest_nonlinear_freq); 905 906 cpufreq_freq_attr_ro(amd_pstate_highest_perf); 907 cpufreq_freq_attr_rw(energy_performance_preference); 908 cpufreq_freq_attr_ro(energy_performance_available_preferences); 909 define_one_global_rw(status); 910 911 static struct freq_attr *amd_pstate_attr[] = { 912 &amd_pstate_max_freq, 913 &amd_pstate_lowest_nonlinear_freq, 914 &amd_pstate_highest_perf, 915 NULL, 916 }; 917 918 static struct freq_attr *amd_pstate_epp_attr[] = { 919 &amd_pstate_max_freq, 920 &amd_pstate_lowest_nonlinear_freq, 921 &amd_pstate_highest_perf, 922 &energy_performance_preference, 923 &energy_performance_available_preferences, 924 NULL, 925 }; 926 927 static struct attribute *pstate_global_attributes[] = { 928 &status.attr, 929 NULL 930 }; 931 932 static const struct attribute_group amd_pstate_global_attr_group = { 933 .attrs = pstate_global_attributes, 934 }; 935 936 static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy) 937 { 938 int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret; 939 struct amd_cpudata *cpudata; 940 struct device *dev; 941 u64 value; 942 943 /* 944 * Resetting PERF_CTL_MSR will put the CPU in P0 frequency, 945 * which is ideal for initialization process. 946 */ 947 amd_perf_ctl_reset(policy->cpu); 948 dev = get_cpu_device(policy->cpu); 949 if (!dev) 950 return -ENODEV; 951 952 cpudata = kzalloc(sizeof(*cpudata), GFP_KERNEL); 953 if (!cpudata) 954 return -ENOMEM; 955 956 cpudata->cpu = policy->cpu; 957 cpudata->epp_policy = 0; 958 959 ret = amd_pstate_init_perf(cpudata); 960 if (ret) 961 goto free_cpudata1; 962 963 min_freq = amd_get_min_freq(cpudata); 964 max_freq = amd_get_max_freq(cpudata); 965 nominal_freq = amd_get_nominal_freq(cpudata); 966 lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata); 967 if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) { 968 dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n", 969 min_freq, max_freq); 970 ret = -EINVAL; 971 goto free_cpudata1; 972 } 973 974 policy->cpuinfo.min_freq = min_freq; 975 policy->cpuinfo.max_freq = max_freq; 976 /* It will be updated by governor */ 977 policy->cur = policy->cpuinfo.min_freq; 978 979 /* Initial processor data capability frequencies */ 980 cpudata->max_freq = max_freq; 981 cpudata->min_freq = min_freq; 982 cpudata->nominal_freq = nominal_freq; 983 cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq; 984 985 policy->driver_data = cpudata; 986 987 cpudata->epp_cached = amd_pstate_get_epp(cpudata, 0); 988 989 policy->min = policy->cpuinfo.min_freq; 990 policy->max = policy->cpuinfo.max_freq; 991 992 /* 993 * Set the policy to powersave to provide a valid fallback value in case 994 * the default cpufreq governor is neither powersave nor performance. 995 */ 996 policy->policy = CPUFREQ_POLICY_POWERSAVE; 997 998 if (boot_cpu_has(X86_FEATURE_CPPC)) { 999 policy->fast_switch_possible = true; 1000 ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, &value); 1001 if (ret) 1002 return ret; 1003 WRITE_ONCE(cpudata->cppc_req_cached, value); 1004 1005 ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1, &value); 1006 if (ret) 1007 return ret; 1008 WRITE_ONCE(cpudata->cppc_cap1_cached, value); 1009 } 1010 amd_pstate_boost_init(cpudata); 1011 1012 return 0; 1013 1014 free_cpudata1: 1015 kfree(cpudata); 1016 return ret; 1017 } 1018 1019 static int amd_pstate_epp_cpu_exit(struct cpufreq_policy *policy) 1020 { 1021 pr_debug("CPU %d exiting\n", policy->cpu); 1022 policy->fast_switch_possible = false; 1023 return 0; 1024 } 1025 1026 static void amd_pstate_epp_init(unsigned int cpu) 1027 { 1028 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); 1029 struct amd_cpudata *cpudata = policy->driver_data; 1030 u32 max_perf, min_perf; 1031 u64 value; 1032 s16 epp; 1033 1034 max_perf = READ_ONCE(cpudata->highest_perf); 1035 min_perf = READ_ONCE(cpudata->lowest_perf); 1036 1037 value = READ_ONCE(cpudata->cppc_req_cached); 1038 1039 if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) 1040 min_perf = max_perf; 1041 1042 /* Initial min/max values for CPPC Performance Controls Register */ 1043 value &= ~AMD_CPPC_MIN_PERF(~0L); 1044 value |= AMD_CPPC_MIN_PERF(min_perf); 1045 1046 value &= ~AMD_CPPC_MAX_PERF(~0L); 1047 value |= AMD_CPPC_MAX_PERF(max_perf); 1048 1049 /* CPPC EPP feature require to set zero to the desire perf bit */ 1050 value &= ~AMD_CPPC_DES_PERF(~0L); 1051 value |= AMD_CPPC_DES_PERF(0); 1052 1053 if (cpudata->epp_policy == cpudata->policy) 1054 goto skip_epp; 1055 1056 cpudata->epp_policy = cpudata->policy; 1057 1058 /* Get BIOS pre-defined epp value */ 1059 epp = amd_pstate_get_epp(cpudata, value); 1060 if (epp < 0) { 1061 /** 1062 * This return value can only be negative for shared_memory 1063 * systems where EPP register read/write not supported. 1064 */ 1065 goto skip_epp; 1066 } 1067 1068 if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) 1069 epp = 0; 1070 1071 /* Set initial EPP value */ 1072 if (boot_cpu_has(X86_FEATURE_CPPC)) { 1073 value &= ~GENMASK_ULL(31, 24); 1074 value |= (u64)epp << 24; 1075 } 1076 1077 WRITE_ONCE(cpudata->cppc_req_cached, value); 1078 amd_pstate_set_epp(cpudata, epp); 1079 skip_epp: 1080 cpufreq_cpu_put(policy); 1081 } 1082 1083 static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy) 1084 { 1085 struct amd_cpudata *cpudata = policy->driver_data; 1086 1087 if (!policy->cpuinfo.max_freq) 1088 return -ENODEV; 1089 1090 pr_debug("set_policy: cpuinfo.max %u policy->max %u\n", 1091 policy->cpuinfo.max_freq, policy->max); 1092 1093 cpudata->policy = policy->policy; 1094 1095 amd_pstate_epp_init(policy->cpu); 1096 1097 return 0; 1098 } 1099 1100 static void amd_pstate_epp_reenable(struct amd_cpudata *cpudata) 1101 { 1102 struct cppc_perf_ctrls perf_ctrls; 1103 u64 value, max_perf; 1104 int ret; 1105 1106 ret = amd_pstate_enable(true); 1107 if (ret) 1108 pr_err("failed to enable amd pstate during resume, return %d\n", ret); 1109 1110 value = READ_ONCE(cpudata->cppc_req_cached); 1111 max_perf = READ_ONCE(cpudata->highest_perf); 1112 1113 if (boot_cpu_has(X86_FEATURE_CPPC)) { 1114 wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value); 1115 } else { 1116 perf_ctrls.max_perf = max_perf; 1117 perf_ctrls.energy_perf = AMD_CPPC_ENERGY_PERF_PREF(cpudata->epp_cached); 1118 cppc_set_perf(cpudata->cpu, &perf_ctrls); 1119 } 1120 } 1121 1122 static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy) 1123 { 1124 struct amd_cpudata *cpudata = policy->driver_data; 1125 1126 pr_debug("AMD CPU Core %d going online\n", cpudata->cpu); 1127 1128 if (cppc_state == AMD_PSTATE_ACTIVE) { 1129 amd_pstate_epp_reenable(cpudata); 1130 cpudata->suspended = false; 1131 } 1132 1133 return 0; 1134 } 1135 1136 static void amd_pstate_epp_offline(struct cpufreq_policy *policy) 1137 { 1138 struct amd_cpudata *cpudata = policy->driver_data; 1139 struct cppc_perf_ctrls perf_ctrls; 1140 int min_perf; 1141 u64 value; 1142 1143 min_perf = READ_ONCE(cpudata->lowest_perf); 1144 value = READ_ONCE(cpudata->cppc_req_cached); 1145 1146 mutex_lock(&amd_pstate_limits_lock); 1147 if (boot_cpu_has(X86_FEATURE_CPPC)) { 1148 cpudata->epp_policy = CPUFREQ_POLICY_UNKNOWN; 1149 1150 /* Set max perf same as min perf */ 1151 value &= ~AMD_CPPC_MAX_PERF(~0L); 1152 value |= AMD_CPPC_MAX_PERF(min_perf); 1153 value &= ~AMD_CPPC_MIN_PERF(~0L); 1154 value |= AMD_CPPC_MIN_PERF(min_perf); 1155 wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value); 1156 } else { 1157 perf_ctrls.desired_perf = 0; 1158 perf_ctrls.max_perf = min_perf; 1159 perf_ctrls.energy_perf = AMD_CPPC_ENERGY_PERF_PREF(HWP_EPP_BALANCE_POWERSAVE); 1160 cppc_set_perf(cpudata->cpu, &perf_ctrls); 1161 } 1162 mutex_unlock(&amd_pstate_limits_lock); 1163 } 1164 1165 static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy) 1166 { 1167 struct amd_cpudata *cpudata = policy->driver_data; 1168 1169 pr_debug("AMD CPU Core %d going offline\n", cpudata->cpu); 1170 1171 if (cpudata->suspended) 1172 return 0; 1173 1174 if (cppc_state == AMD_PSTATE_ACTIVE) 1175 amd_pstate_epp_offline(policy); 1176 1177 return 0; 1178 } 1179 1180 static int amd_pstate_epp_verify_policy(struct cpufreq_policy_data *policy) 1181 { 1182 cpufreq_verify_within_cpu_limits(policy); 1183 pr_debug("policy_max =%d, policy_min=%d\n", policy->max, policy->min); 1184 return 0; 1185 } 1186 1187 static int amd_pstate_epp_suspend(struct cpufreq_policy *policy) 1188 { 1189 struct amd_cpudata *cpudata = policy->driver_data; 1190 int ret; 1191 1192 /* avoid suspending when EPP is not enabled */ 1193 if (cppc_state != AMD_PSTATE_ACTIVE) 1194 return 0; 1195 1196 /* set this flag to avoid setting core offline*/ 1197 cpudata->suspended = true; 1198 1199 /* disable CPPC in lowlevel firmware */ 1200 ret = amd_pstate_enable(false); 1201 if (ret) 1202 pr_err("failed to suspend, return %d\n", ret); 1203 1204 return 0; 1205 } 1206 1207 static int amd_pstate_epp_resume(struct cpufreq_policy *policy) 1208 { 1209 struct amd_cpudata *cpudata = policy->driver_data; 1210 1211 if (cpudata->suspended) { 1212 mutex_lock(&amd_pstate_limits_lock); 1213 1214 /* enable amd pstate from suspend state*/ 1215 amd_pstate_epp_reenable(cpudata); 1216 1217 mutex_unlock(&amd_pstate_limits_lock); 1218 1219 cpudata->suspended = false; 1220 } 1221 1222 return 0; 1223 } 1224 1225 static struct cpufreq_driver amd_pstate_driver = { 1226 .flags = CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS, 1227 .verify = amd_pstate_verify, 1228 .target = amd_pstate_target, 1229 .init = amd_pstate_cpu_init, 1230 .exit = amd_pstate_cpu_exit, 1231 .suspend = amd_pstate_cpu_suspend, 1232 .resume = amd_pstate_cpu_resume, 1233 .set_boost = amd_pstate_set_boost, 1234 .name = "amd-pstate", 1235 .attr = amd_pstate_attr, 1236 }; 1237 1238 static struct cpufreq_driver amd_pstate_epp_driver = { 1239 .flags = CPUFREQ_CONST_LOOPS, 1240 .verify = amd_pstate_epp_verify_policy, 1241 .setpolicy = amd_pstate_epp_set_policy, 1242 .init = amd_pstate_epp_cpu_init, 1243 .exit = amd_pstate_epp_cpu_exit, 1244 .offline = amd_pstate_epp_cpu_offline, 1245 .online = amd_pstate_epp_cpu_online, 1246 .suspend = amd_pstate_epp_suspend, 1247 .resume = amd_pstate_epp_resume, 1248 .name = "amd_pstate_epp", 1249 .attr = amd_pstate_epp_attr, 1250 }; 1251 1252 static int __init amd_pstate_init(void) 1253 { 1254 int ret; 1255 1256 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) 1257 return -ENODEV; 1258 /* 1259 * by default the pstate driver is disabled to load 1260 * enable the amd_pstate passive mode driver explicitly 1261 * with amd_pstate=passive or other modes in kernel command line 1262 */ 1263 if (cppc_state == AMD_PSTATE_DISABLE) { 1264 pr_info("driver load is disabled, boot with specific mode to enable this\n"); 1265 return -ENODEV; 1266 } 1267 1268 if (!acpi_cpc_valid()) { 1269 pr_warn_once("the _CPC object is not present in SBIOS or ACPI disabled\n"); 1270 return -ENODEV; 1271 } 1272 1273 /* don't keep reloading if cpufreq_driver exists */ 1274 if (cpufreq_get_current_driver()) 1275 return -EEXIST; 1276 1277 /* capability check */ 1278 if (boot_cpu_has(X86_FEATURE_CPPC)) { 1279 pr_debug("AMD CPPC MSR based functionality is supported\n"); 1280 if (cppc_state == AMD_PSTATE_PASSIVE) 1281 current_pstate_driver->adjust_perf = amd_pstate_adjust_perf; 1282 } else { 1283 pr_debug("AMD CPPC shared memory based functionality is supported\n"); 1284 static_call_update(amd_pstate_enable, cppc_enable); 1285 static_call_update(amd_pstate_init_perf, cppc_init_perf); 1286 static_call_update(amd_pstate_update_perf, cppc_update_perf); 1287 } 1288 1289 /* enable amd pstate feature */ 1290 ret = amd_pstate_enable(true); 1291 if (ret) { 1292 pr_err("failed to enable with return %d\n", ret); 1293 return ret; 1294 } 1295 1296 ret = cpufreq_register_driver(current_pstate_driver); 1297 if (ret) 1298 pr_err("failed to register with return %d\n", ret); 1299 1300 amd_pstate_kobj = kobject_create_and_add("amd_pstate", &cpu_subsys.dev_root->kobj); 1301 if (!amd_pstate_kobj) { 1302 ret = -EINVAL; 1303 pr_err("global sysfs registration failed.\n"); 1304 goto kobject_free; 1305 } 1306 1307 ret = sysfs_create_group(amd_pstate_kobj, &amd_pstate_global_attr_group); 1308 if (ret) { 1309 pr_err("sysfs attribute export failed with error %d.\n", ret); 1310 goto global_attr_free; 1311 } 1312 1313 return ret; 1314 1315 global_attr_free: 1316 kobject_put(amd_pstate_kobj); 1317 kobject_free: 1318 cpufreq_unregister_driver(current_pstate_driver); 1319 return ret; 1320 } 1321 device_initcall(amd_pstate_init); 1322 1323 static int __init amd_pstate_param(char *str) 1324 { 1325 size_t size; 1326 int mode_idx; 1327 1328 if (!str) 1329 return -EINVAL; 1330 1331 size = strlen(str); 1332 mode_idx = get_mode_idx_from_str(str, size); 1333 1334 if (mode_idx >= AMD_PSTATE_DISABLE && mode_idx < AMD_PSTATE_MAX) { 1335 cppc_state = mode_idx; 1336 if (cppc_state == AMD_PSTATE_DISABLE) 1337 pr_info("driver is explicitly disabled\n"); 1338 1339 if (cppc_state == AMD_PSTATE_ACTIVE) 1340 current_pstate_driver = &amd_pstate_epp_driver; 1341 1342 if (cppc_state == AMD_PSTATE_PASSIVE) 1343 current_pstate_driver = &amd_pstate_driver; 1344 1345 return 0; 1346 } 1347 1348 return -EINVAL; 1349 } 1350 early_param("amd_pstate", amd_pstate_param); 1351 1352 MODULE_AUTHOR("Huang Rui <ray.huang@amd.com>"); 1353 MODULE_DESCRIPTION("AMD Processor P-state Frequency Driver"); 1354