1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * CPPC (Collaborative Processor Performance Control) driver for 4 * interfacing with the CPUfreq layer and governors. See 5 * cppc_acpi.c for CPPC specific methods. 6 * 7 * (C) Copyright 2014, 2015 Linaro Ltd. 8 * Author: Ashwin Chaugule <ashwin.chaugule@linaro.org> 9 */ 10 11 #define pr_fmt(fmt) "CPPC Cpufreq:" fmt 12 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/delay.h> 16 #include <linux/cpu.h> 17 #include <linux/cpufreq.h> 18 #include <linux/dmi.h> 19 #include <linux/time.h> 20 #include <linux/vmalloc.h> 21 22 #include <asm/unaligned.h> 23 24 #include <acpi/cppc_acpi.h> 25 26 /* Minimum struct length needed for the DMI processor entry we want */ 27 #define DMI_ENTRY_PROCESSOR_MIN_LENGTH 48 28 29 /* Offest in the DMI processor structure for the max frequency */ 30 #define DMI_PROCESSOR_MAX_SPEED 0x14 31 32 /* 33 * These structs contain information parsed from per CPU 34 * ACPI _CPC structures. 35 * e.g. For each CPU the highest, lowest supported 36 * performance capabilities, desired performance level 37 * requested etc. 38 */ 39 static struct cppc_cpudata **all_cpu_data; 40 static bool boost_supported; 41 42 struct cppc_workaround_oem_info { 43 char oem_id[ACPI_OEM_ID_SIZE + 1]; 44 char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1]; 45 u32 oem_revision; 46 }; 47 48 static bool apply_hisi_workaround; 49 50 static struct cppc_workaround_oem_info wa_info[] = { 51 { 52 .oem_id = "HISI ", 53 .oem_table_id = "HIP07 ", 54 .oem_revision = 0, 55 }, { 56 .oem_id = "HISI ", 57 .oem_table_id = "HIP08 ", 58 .oem_revision = 0, 59 } 60 }; 61 62 static unsigned int cppc_cpufreq_perf_to_khz(struct cppc_cpudata *cpu, 63 unsigned int perf); 64 65 /* 66 * HISI platform does not support delivered performance counter and 67 * reference performance counter. It can calculate the performance using the 68 * platform specific mechanism. We reuse the desired performance register to 69 * store the real performance calculated by the platform. 70 */ 71 static unsigned int hisi_cppc_cpufreq_get_rate(unsigned int cpunum) 72 { 73 struct cppc_cpudata *cpudata = all_cpu_data[cpunum]; 74 u64 desired_perf; 75 int ret; 76 77 ret = cppc_get_desired_perf(cpunum, &desired_perf); 78 if (ret < 0) 79 return -EIO; 80 81 return cppc_cpufreq_perf_to_khz(cpudata, desired_perf); 82 } 83 84 static void cppc_check_hisi_workaround(void) 85 { 86 struct acpi_table_header *tbl; 87 acpi_status status = AE_OK; 88 int i; 89 90 status = acpi_get_table(ACPI_SIG_PCCT, 0, &tbl); 91 if (ACPI_FAILURE(status) || !tbl) 92 return; 93 94 for (i = 0; i < ARRAY_SIZE(wa_info); i++) { 95 if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE) && 96 !memcmp(wa_info[i].oem_table_id, tbl->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) && 97 wa_info[i].oem_revision == tbl->oem_revision) { 98 apply_hisi_workaround = true; 99 break; 100 } 101 } 102 103 acpi_put_table(tbl); 104 } 105 106 /* Callback function used to retrieve the max frequency from DMI */ 107 static void cppc_find_dmi_mhz(const struct dmi_header *dm, void *private) 108 { 109 const u8 *dmi_data = (const u8 *)dm; 110 u16 *mhz = (u16 *)private; 111 112 if (dm->type == DMI_ENTRY_PROCESSOR && 113 dm->length >= DMI_ENTRY_PROCESSOR_MIN_LENGTH) { 114 u16 val = (u16)get_unaligned((const u16 *) 115 (dmi_data + DMI_PROCESSOR_MAX_SPEED)); 116 *mhz = val > *mhz ? val : *mhz; 117 } 118 } 119 120 /* Look up the max frequency in DMI */ 121 static u64 cppc_get_dmi_max_khz(void) 122 { 123 u16 mhz = 0; 124 125 dmi_walk(cppc_find_dmi_mhz, &mhz); 126 127 /* 128 * Real stupid fallback value, just in case there is no 129 * actual value set. 130 */ 131 mhz = mhz ? mhz : 1; 132 133 return (1000 * mhz); 134 } 135 136 /* 137 * If CPPC lowest_freq and nominal_freq registers are exposed then we can 138 * use them to convert perf to freq and vice versa 139 * 140 * If the perf/freq point lies between Nominal and Lowest, we can treat 141 * (Low perf, Low freq) and (Nom Perf, Nom freq) as 2D co-ordinates of a line 142 * and extrapolate the rest 143 * For perf/freq > Nominal, we use the ratio perf:freq at Nominal for conversion 144 */ 145 static unsigned int cppc_cpufreq_perf_to_khz(struct cppc_cpudata *cpu, 146 unsigned int perf) 147 { 148 static u64 max_khz; 149 struct cppc_perf_caps *caps = &cpu->perf_caps; 150 u64 mul, div; 151 152 if (caps->lowest_freq && caps->nominal_freq) { 153 if (perf >= caps->nominal_perf) { 154 mul = caps->nominal_freq; 155 div = caps->nominal_perf; 156 } else { 157 mul = caps->nominal_freq - caps->lowest_freq; 158 div = caps->nominal_perf - caps->lowest_perf; 159 } 160 } else { 161 if (!max_khz) 162 max_khz = cppc_get_dmi_max_khz(); 163 mul = max_khz; 164 div = cpu->perf_caps.highest_perf; 165 } 166 return (u64)perf * mul / div; 167 } 168 169 static unsigned int cppc_cpufreq_khz_to_perf(struct cppc_cpudata *cpu, 170 unsigned int freq) 171 { 172 static u64 max_khz; 173 struct cppc_perf_caps *caps = &cpu->perf_caps; 174 u64 mul, div; 175 176 if (caps->lowest_freq && caps->nominal_freq) { 177 if (freq >= caps->nominal_freq) { 178 mul = caps->nominal_perf; 179 div = caps->nominal_freq; 180 } else { 181 mul = caps->lowest_perf; 182 div = caps->lowest_freq; 183 } 184 } else { 185 if (!max_khz) 186 max_khz = cppc_get_dmi_max_khz(); 187 mul = cpu->perf_caps.highest_perf; 188 div = max_khz; 189 } 190 191 return (u64)freq * mul / div; 192 } 193 194 static int cppc_cpufreq_set_target(struct cpufreq_policy *policy, 195 unsigned int target_freq, 196 unsigned int relation) 197 { 198 struct cppc_cpudata *cpu; 199 struct cpufreq_freqs freqs; 200 u32 desired_perf; 201 int ret = 0; 202 203 cpu = all_cpu_data[policy->cpu]; 204 205 desired_perf = cppc_cpufreq_khz_to_perf(cpu, target_freq); 206 /* Return if it is exactly the same perf */ 207 if (desired_perf == cpu->perf_ctrls.desired_perf) 208 return ret; 209 210 cpu->perf_ctrls.desired_perf = desired_perf; 211 freqs.old = policy->cur; 212 freqs.new = target_freq; 213 214 cpufreq_freq_transition_begin(policy, &freqs); 215 ret = cppc_set_perf(cpu->cpu, &cpu->perf_ctrls); 216 cpufreq_freq_transition_end(policy, &freqs, ret != 0); 217 218 if (ret) 219 pr_debug("Failed to set target on CPU:%d. ret:%d\n", 220 cpu->cpu, ret); 221 222 return ret; 223 } 224 225 static int cppc_verify_policy(struct cpufreq_policy_data *policy) 226 { 227 cpufreq_verify_within_cpu_limits(policy); 228 return 0; 229 } 230 231 static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy) 232 { 233 int cpu_num = policy->cpu; 234 struct cppc_cpudata *cpu = all_cpu_data[cpu_num]; 235 int ret; 236 237 cpu->perf_ctrls.desired_perf = cpu->perf_caps.lowest_perf; 238 239 ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls); 240 if (ret) 241 pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n", 242 cpu->perf_caps.lowest_perf, cpu_num, ret); 243 } 244 245 /* 246 * The PCC subspace describes the rate at which platform can accept commands 247 * on the shared PCC channel (including READs which do not count towards freq 248 * trasition requests), so ideally we need to use the PCC values as a fallback 249 * if we don't have a platform specific transition_delay_us 250 */ 251 #ifdef CONFIG_ARM64 252 #include <asm/cputype.h> 253 254 static unsigned int cppc_cpufreq_get_transition_delay_us(int cpu) 255 { 256 unsigned long implementor = read_cpuid_implementor(); 257 unsigned long part_num = read_cpuid_part_number(); 258 unsigned int delay_us = 0; 259 260 switch (implementor) { 261 case ARM_CPU_IMP_QCOM: 262 switch (part_num) { 263 case QCOM_CPU_PART_FALKOR_V1: 264 case QCOM_CPU_PART_FALKOR: 265 delay_us = 10000; 266 break; 267 default: 268 delay_us = cppc_get_transition_latency(cpu) / NSEC_PER_USEC; 269 break; 270 } 271 break; 272 default: 273 delay_us = cppc_get_transition_latency(cpu) / NSEC_PER_USEC; 274 break; 275 } 276 277 return delay_us; 278 } 279 280 #else 281 282 static unsigned int cppc_cpufreq_get_transition_delay_us(int cpu) 283 { 284 return cppc_get_transition_latency(cpu) / NSEC_PER_USEC; 285 } 286 #endif 287 288 static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy) 289 { 290 struct cppc_cpudata *cpu; 291 unsigned int cpu_num = policy->cpu; 292 int ret = 0; 293 294 cpu = all_cpu_data[policy->cpu]; 295 296 cpu->cpu = cpu_num; 297 ret = cppc_get_perf_caps(policy->cpu, &cpu->perf_caps); 298 299 if (ret) { 300 pr_debug("Err reading CPU%d perf capabilities. ret:%d\n", 301 cpu_num, ret); 302 return ret; 303 } 304 305 /* Convert the lowest and nominal freq from MHz to KHz */ 306 cpu->perf_caps.lowest_freq *= 1000; 307 cpu->perf_caps.nominal_freq *= 1000; 308 309 /* 310 * Set min to lowest nonlinear perf to avoid any efficiency penalty (see 311 * Section 8.4.7.1.1.5 of ACPI 6.1 spec) 312 */ 313 policy->min = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.lowest_nonlinear_perf); 314 policy->max = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.nominal_perf); 315 316 /* 317 * Set cpuinfo.min_freq to Lowest to make the full range of performance 318 * available if userspace wants to use any perf between lowest & lowest 319 * nonlinear perf 320 */ 321 policy->cpuinfo.min_freq = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.lowest_perf); 322 policy->cpuinfo.max_freq = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.nominal_perf); 323 324 policy->transition_delay_us = cppc_cpufreq_get_transition_delay_us(cpu_num); 325 policy->shared_type = cpu->shared_type; 326 327 if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) { 328 int i; 329 330 cpumask_copy(policy->cpus, cpu->shared_cpu_map); 331 332 for_each_cpu(i, policy->cpus) { 333 if (unlikely(i == policy->cpu)) 334 continue; 335 336 memcpy(&all_cpu_data[i]->perf_caps, &cpu->perf_caps, 337 sizeof(cpu->perf_caps)); 338 } 339 } else if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL) { 340 /* Support only SW_ANY for now. */ 341 pr_debug("Unsupported CPU co-ord type\n"); 342 return -EFAULT; 343 } 344 345 cpu->cur_policy = policy; 346 347 /* 348 * If 'highest_perf' is greater than 'nominal_perf', we assume CPU Boost 349 * is supported. 350 */ 351 if (cpu->perf_caps.highest_perf > cpu->perf_caps.nominal_perf) 352 boost_supported = true; 353 354 /* Set policy->cur to max now. The governors will adjust later. */ 355 policy->cur = cppc_cpufreq_perf_to_khz(cpu, 356 cpu->perf_caps.highest_perf); 357 cpu->perf_ctrls.desired_perf = cpu->perf_caps.highest_perf; 358 359 ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls); 360 if (ret) 361 pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n", 362 cpu->perf_caps.highest_perf, cpu_num, ret); 363 364 return ret; 365 } 366 367 static inline u64 get_delta(u64 t1, u64 t0) 368 { 369 if (t1 > t0 || t0 > ~(u32)0) 370 return t1 - t0; 371 372 return (u32)t1 - (u32)t0; 373 } 374 375 static int cppc_get_rate_from_fbctrs(struct cppc_cpudata *cpu, 376 struct cppc_perf_fb_ctrs fb_ctrs_t0, 377 struct cppc_perf_fb_ctrs fb_ctrs_t1) 378 { 379 u64 delta_reference, delta_delivered; 380 u64 reference_perf, delivered_perf; 381 382 reference_perf = fb_ctrs_t0.reference_perf; 383 384 delta_reference = get_delta(fb_ctrs_t1.reference, 385 fb_ctrs_t0.reference); 386 delta_delivered = get_delta(fb_ctrs_t1.delivered, 387 fb_ctrs_t0.delivered); 388 389 /* Check to avoid divide-by zero */ 390 if (delta_reference || delta_delivered) 391 delivered_perf = (reference_perf * delta_delivered) / 392 delta_reference; 393 else 394 delivered_perf = cpu->perf_ctrls.desired_perf; 395 396 return cppc_cpufreq_perf_to_khz(cpu, delivered_perf); 397 } 398 399 static unsigned int cppc_cpufreq_get_rate(unsigned int cpunum) 400 { 401 struct cppc_perf_fb_ctrs fb_ctrs_t0 = {0}, fb_ctrs_t1 = {0}; 402 struct cppc_cpudata *cpu = all_cpu_data[cpunum]; 403 int ret; 404 405 if (apply_hisi_workaround) 406 return hisi_cppc_cpufreq_get_rate(cpunum); 407 408 ret = cppc_get_perf_ctrs(cpunum, &fb_ctrs_t0); 409 if (ret) 410 return ret; 411 412 udelay(2); /* 2usec delay between sampling */ 413 414 ret = cppc_get_perf_ctrs(cpunum, &fb_ctrs_t1); 415 if (ret) 416 return ret; 417 418 return cppc_get_rate_from_fbctrs(cpu, fb_ctrs_t0, fb_ctrs_t1); 419 } 420 421 static int cppc_cpufreq_set_boost(struct cpufreq_policy *policy, int state) 422 { 423 struct cppc_cpudata *cpudata; 424 int ret; 425 426 if (!boost_supported) { 427 pr_err("BOOST not supported by CPU or firmware\n"); 428 return -EINVAL; 429 } 430 431 cpudata = all_cpu_data[policy->cpu]; 432 if (state) 433 policy->max = cppc_cpufreq_perf_to_khz(cpudata, 434 cpudata->perf_caps.highest_perf); 435 else 436 policy->max = cppc_cpufreq_perf_to_khz(cpudata, 437 cpudata->perf_caps.nominal_perf); 438 policy->cpuinfo.max_freq = policy->max; 439 440 ret = freq_qos_update_request(policy->max_freq_req, policy->max); 441 if (ret < 0) 442 return ret; 443 444 return 0; 445 } 446 447 static struct cpufreq_driver cppc_cpufreq_driver = { 448 .flags = CPUFREQ_CONST_LOOPS, 449 .verify = cppc_verify_policy, 450 .target = cppc_cpufreq_set_target, 451 .get = cppc_cpufreq_get_rate, 452 .init = cppc_cpufreq_cpu_init, 453 .stop_cpu = cppc_cpufreq_stop_cpu, 454 .set_boost = cppc_cpufreq_set_boost, 455 .name = "cppc_cpufreq", 456 }; 457 458 static int __init cppc_cpufreq_init(void) 459 { 460 int i, ret = 0; 461 struct cppc_cpudata *cpu; 462 463 if (acpi_disabled) 464 return -ENODEV; 465 466 all_cpu_data = kcalloc(num_possible_cpus(), sizeof(void *), 467 GFP_KERNEL); 468 if (!all_cpu_data) 469 return -ENOMEM; 470 471 for_each_possible_cpu(i) { 472 all_cpu_data[i] = kzalloc(sizeof(struct cppc_cpudata), GFP_KERNEL); 473 if (!all_cpu_data[i]) 474 goto out; 475 476 cpu = all_cpu_data[i]; 477 if (!zalloc_cpumask_var(&cpu->shared_cpu_map, GFP_KERNEL)) 478 goto out; 479 } 480 481 ret = acpi_get_psd_map(all_cpu_data); 482 if (ret) { 483 pr_debug("Error parsing PSD data. Aborting cpufreq registration.\n"); 484 goto out; 485 } 486 487 cppc_check_hisi_workaround(); 488 489 ret = cpufreq_register_driver(&cppc_cpufreq_driver); 490 if (ret) 491 goto out; 492 493 return ret; 494 495 out: 496 for_each_possible_cpu(i) { 497 cpu = all_cpu_data[i]; 498 if (!cpu) 499 break; 500 free_cpumask_var(cpu->shared_cpu_map); 501 kfree(cpu); 502 } 503 504 kfree(all_cpu_data); 505 return -ENODEV; 506 } 507 508 static void __exit cppc_cpufreq_exit(void) 509 { 510 struct cppc_cpudata *cpu; 511 int i; 512 513 cpufreq_unregister_driver(&cppc_cpufreq_driver); 514 515 for_each_possible_cpu(i) { 516 cpu = all_cpu_data[i]; 517 free_cpumask_var(cpu->shared_cpu_map); 518 kfree(cpu); 519 } 520 521 kfree(all_cpu_data); 522 } 523 524 module_exit(cppc_cpufreq_exit); 525 MODULE_AUTHOR("Ashwin Chaugule"); 526 MODULE_DESCRIPTION("CPUFreq driver based on the ACPI CPPC v5.0+ spec"); 527 MODULE_LICENSE("GPL"); 528 529 late_initcall(cppc_cpufreq_init); 530 531 static const struct acpi_device_id cppc_acpi_ids[] __used = { 532 {ACPI_PROCESSOR_DEVICE_HID, }, 533 {} 534 }; 535 536 MODULE_DEVICE_TABLE(acpi, cppc_acpi_ids); 537